Recently I was involved in an online discussion on the subject of ordination. It revolved around the use of the word ordination by the Western Buddhist Order. The main contention was that the word 'ordained' should be restricted to bhikkhus (for the sake of brevity I'll use the masculine and Pāli ) . So what I propose to do is work through the various relevant terms and then see what conclusions can be drawn.
'Bhikkhu' is used like a title these days but was originally an adjective descriptive of a lifestyle. Literally it means 'beggar' or someone who lives off alms - a very low status, not to say ritually polluted, occupation in both ancient and modern India.  In the Buddha's day this meant going from door to door with a bowl collecting leftovers, but in modern times there are a variety of approaches -for example Tibetan monks often buy food and cook for themselves; while in some Theravāda monasteries lay people bring food to the bhikkhus and feed them in situ. Some bhikkhus maintain the practice of going out for alms, but this is highly formalised and there is no risk involved.
The Buddha originally made someone a bhikkhu simply by saying to them: 'ehi' - come! (second person imperative of √i 'to go' with ā- prefix signifying motion towards). However this was soon formalised into a two stage process. First a person became a sāmaṇera - this word derives from samaṇa (√śram) meaning a wanderer and implying a religious ascetic. The ceremony, also sometimes called an ordination, in Pāli is sāmaṇera-pabbajjā. Pabbajjā (from pa + √vraj 'to proceed') means 'going forth' and refers to the act of leaving home to become a paribbājjaka 'someone who wanders around'. A 'vagrant' in today's language. PED refers to the pabbajjā ceremony as an 'ordination'. Going forth was a distinct and important phase of religious life as can be seen in the Buddha's biography where the episode is highly elaborated. It was becoming a vagrant that was the really radical step - because in doing so one gave up the comforts of home, and the protection and support of one's family. For later Buddhists it meant taking on the sāmaṇera precepts , dressing in white robes, shaving one's head, and living a cenobitical lifestyle. In English this is sometimes referred to as being a 'novice' monk.
The second phase, which often follows immediately afterwards these days, is the upasampadā, usually referred to in English as the 'higher ordination' and a bhikkhu will often refer to themselves as 'fully ordained'. This word means 'taking upon oneself' and in this context it means taking upon oneself the patimokkha precepts or restraints. The original metaphor underlying this word 'patimokkha', according to Prof. Gombrich, is a medical one indicating a purgative that could return a person to health , meaning in this case ethical 'health' or purity. Because the Vinaya did not reach its final form for some time after the Buddha, it exists in several distinct recensions with greatly varying number of rules. Theravādins observe 227 for instance, while those who follow a Sarvastivādin Vinaya (some Tibetan monks) observe 250 rules. Most of the rules are relatively minor and infringing them is taken quite lightly. Many are of no ethical significance at all and are specific to cultural mores in the Ganges valley more than 2000 years ago, often being developed after complaints about the bhikkhus from the laity. However conservatism and formalism has resulted in the retention of rules even when they are apparently meaningless. It is akin to the rules of conduct in parts of the old testament in that respect. Many of the rules were instituted simply to distinguish bhikkhus from samaṇas of other sects, or brāhmaṇas or lay people etc., that is they are more about identity. The qualifiers 'higher' and 'fully' point to the overlooked fact that the sāmaṇera-pabbajjā is also seen as an ordination.
The traditionalists argue that on receiving the upasampadā, a sāmaṇera has been accepted into the bhikkhu-saṅgha. Translating into English we might say something like: at his ordination the novice has been ordained into the order of monks. It has been argued that 'ordination', 'ordain, and 'order' are the specific province of the bhikkhu and should not be used any other way in a Buddhist context. The main point seemed to be that it was important to distinguish bhikkhus from other lifestyles, although it was not clear why we should do so, though it's an ancient concern as it occurs in the Pāli canon. Apart from the traditional reference to the sāmaṇera ordination, my argument against this is threefold: firstly that the word admits many other uses; secondly, that it is conventionally used differently by Buddhists anyway; and thirdly, that in seeking to appropriate the term Buddhists are propagating an elitism which is out of touch with reality. So let's begin by looking at what the English terms mean. 
'Order' in the sense of "a group of person living under a religious rule" dates from the 13th century. This and the other words we are considering derive from the Latin ordo meaning 'row, rank, series, arrangement', originally 'a row of threads in a loom'. Hence we can 'put things in order'. Clearly order in our sense referred to Christian monastics who typically adopted an ordered and regular lifestyle, spelled out in their rule, which not only laid down moral rules but also dictated what prayer and services were said and when. This began to happen as early as the 4th century CE. We can see that different orders of monastics took on very different rules, but that the term 'order' still applied because they all had in common conformance to a rule.
The verb 'ordain' meaning "to appoint or admit to the ministry of the Church" also dates from the 13th century. Many dictionaries (including Collins) describe 'ordain' in this context as the "conferring of Holy orders". This refers to the fact that the Roman Catholic church considered ordination a sacrament. Protestant churches, on the whole, do not consider ordination a sacrament though they still use 'ordain' to refer to conferring the office of minister or priest. Positions within an order, such as bishop or cardinal, were not sacramental, but only offices and titles. One is not ordained a bishop, one is promoted. Also novice Christian monks are not ordained at all in contrast to the sāmaṇera.
Ordination is simply the ceremony by which one is accepted into an order, most typically a religious order. The rule and denomination of the order were not relevant to the use of the term 'ordain'. A Pentecostal minister or a Catholic priest are both ordained. The key part of ordination is being accepted into an order and following a religious rule. Bhikkhus do conform to this usage, and although it's not clear who first used 'ordination' to translate upasampadā it does work. However bhikkhu ordination is a special case of ordination rather than an epitome, or acme. So let's turn to the use in a more specifically Buddhist context.
Ordination also serves for Buddhists following other lifestyles who commit themselves to a 'rule'. Particularly in the English speaking Buddhist world the use of the term ordination is commonplace. For example, an American acquaintance, Al, describes himself as "an ordained Zen Priest" (his lineage is in fact Korean). Priest, by the way, comes from a Latin word presbyter meaning 'elder'. The Japanese move away from upasampadā ordinations probably stems from the Tendai School whose founder Saichō formally abandoned the Vinaya in favour of a Bodhisattva Ordination in 822 CE. (Note that even in settings where the Vinaya ordination is the standard, this taking of the bodhisattva precepts is still referred to as an ordination.) Saichō met a great deal of opposition from the Buddhist establishment of the day, but he had the Emperor on his side precisely because the Buddhist establishment were wealthy and interfered in politics. In the WBO also we refer to having been ordained into an order. At our ordination ceremony we undertake to follow our set of ten precepts (traditionally known as dasakusaladhammā or dasakusalakammapathā), and an additional four 'acceptance vows'  which constitute the 'rule' by which we all vow to live. So the WBO order/ordination certainly fit the English usage, as well as the Japanese Buddhist precedent.
Note here there is a distinction between joining an order and becoming a Buddhist generally. Even though all Buddhists undertake to keep precepts, ordination, as defined in the WBO, requires that the practice of the precepts, including repairing breaches, be thorough-going and effective. One has to be not only willing, but demonstrably able, to take on the precepts for life.
So given that the English usage is pretty straight-forward and there are numerous Buddhist precedents in the present and dating back almost 1200 years: why the continued insistence that only bhikkhus can claim to be ordained? My answer to this is privilege.
Bhikkhus are outwardly marked in many ways: shaved head, robes, and dietary habits for instance. These external signs of ordination amount to lifestyle choices. One can be outwardly a bhikkhu and inwardly a lay person (see e.g. Dhammapada, Chp 19). Sangharakshita abandoned the monk/lay divide because on the one hand he met so many Theravādin bhikkhus who did not practice Buddhism, and on the other hand he met many Tibetan lay lamas who very much did. Sangharakshita was also influenced by the example of Anagārika Dharmapala (pictured above) who he refers to as a man of "towering moral and spiritual grandeur".  Dharmapala was also critical of established traditions and adopted the invented title Anagārika to indicate a committed Buddhist who was neither monk nor lay. It became clear that being a monk was important when it came to the practice of the Dharma, what was important was commitment and application.
Lay people give the clergy donations in order to create merit and the higher the social status of the recipient the greater the merit. So laypeople have played along with the superstition and we are being asked to perpetuate it in the west. The generosity of laypeople has in some places led to the accumulation of wealth and often political influence, not to say political control. The irony here is heavy. The initial idea of becoming a sāmaṇera was to leave behind concerns with property and power: nowadays monasteries are often centres of both. I've seen more than one news story of monks fighting pitched battles for the control of a monastery.
One of the traditional roles of monks was to teach. However monks have in many cases become intermediaries between the people and liberation rather than facilitators. Monks are seen as necessary for the 'administering' of the refuges and precepts for instance; or they perform religious activities such as pujas on behalf of spectators (I've been invited to watch a senior lama perform a puja for instance); or as officiants at what are essentially secular ceremonial occasions, such as weddings. Monks are in fact operating as priests in the pejorative sense of that word.
Monks, especially as preservers of texts, became arbiters of orthodoxy, i.e. correct opinions. And the correct opinion is that monks deserve a special status because of their role in society. From the point of view of Western social mores, this appears to be corrupt. We preserve texts through mass printing and often look to secular scholars for translations and exegesis precisely because they apply the methods of higher criticism. Often times the tradition demonstrably does not understand its own texts. In Pāli for example, Buddhaghosa was at times confused by the text and fudged the commentary; where there is a difficult reading in a Pāli text it is often simply left out of the Chinese translation.
Traditional Buddhism often preserves the social mores and superstitions of one or other ancient Asian culture. One of which is the high social status of bhikkhus. As English speaking Westerners we are in a position to decide how relevant that culture is, but the arbiters of this are often the same men who benefit from the privileged status, the bhikkhus. I'm not keen to abandon my cultural heritage, especially the values and achievements of The Enlightenment. Traditional Buddhism with its feudal hierarchies and institutionalised privilege seems to point back to pre-Enlightenment values. One glaring area of disparity is that traditional Buddhism is distinctly anti-women.
I'm critical of the system: there are many reasons to support monks, but none to worship them or automatically treat them as superior human beings. On the other hand I've met or know of bhikkhus I respect and see no reason to take the other extreme and automatically treat bhikkhus with disrespect. As I wrote in How to Spot an Arahant, it takes time to evaluate the spiritual maturity of anyone even if they have all the trappings. In the mean time we have precepts to live up to.
To sum up (this overly long post) I've looked at how the word ordination is used in context and shown that bhikkhus have no special claim on that term. I've shown that within Buddhism there are precedents for using the term in other ways dating back to Saichō in 822 CE. These seem reasonably clear. But still the very idea that someone who was not a bhikkhu might call themselves 'ordained' seemed to cause some people considerable distress. I speculate that the reason for this is that the system of renunciate bhikkhus having left behind the world, has been replaced by an elite who preserve privilege that sometimes translates into power. They have historically controlled orthodoxy in ways that benefit them as a group. The term for this is "provider capture".
Experience suggests I am either preaching to the converted or the intractable on this issue. My colleagues on the one hand, and other Buddhists on the other. The history of Buddhism is one of change, development, reform and even syncretism. Indeed our credo, if we have one, is "everything changes". This slogan was first enunciated by one of the greatest anti-establishment thinkers of all time, who systematically demolished every system he came across. There is an obvious tension between the inevitability of change, the uncertainty this leaves us with, the imperative to adapt to Western culture; and the powerful desire for unchanging traditions and institutions and the certainty (and I argue privilege and power) they represent. So we are faced with social and religious conservatism from a group which loudly proclaims that everything changes. Perhaps our credo must be modified to exclude certain institutions? Or perhaps it is time to acknowledge the anachronism and move on. I'm voting with my feet.
- Pāli: masc. bhikkhu, fem. bhikkunī; Sanskrit: bhikṣu, bhikṣuṇī. A feature of traditional Buddhism is a decidedly anti-woman streak, though there is now a revival of bhikṣuṇī ordinations. For my views of women's ordinations see Women and Buddhist Ordination.
- Anyone who doubts this might like to read the account of what Sāriputta's mother thought of his going forth in Nyanaponika and Hecker. Great Disciples of the Buddha, p.34; or consider the story of the Buddha leaving home in the version found in the Ariyapariyesanā Sutta (MN 21), Bhikkhu Thanissaro translates:
"So, at a later time, while still young, a black-haired young man endowed with the blessings of youth in the first stage of life — and while my parents, unwilling, were crying with tears streaming down their faces — I shaved off my hair & beard, put on the ochre robe and went forth from the home life into homelessness".
- The 10 precepts are abstaining from: harming living beings; taking the not given; sexual intercourse; lying; liquor and intoxicants; eating after noon; dancing, singing, and musical performances; using garlands, unguents, or ornaments; sitting and sleeping on a high or broad bed; handling gold and silver.
- Gombrich, Richard. “Pātimokkha: Purgative,” in Studies in Buddhism and culture in honour of Professor Dr. Egaku Mayeda on his sixty-fifth birthday, edited by The Editorial Committee of the Felicitation Volume for Professor Dr. Egaku Mayeda. Tokyo: Sankibo Busshorin, 31-38, 1991. I made use of this research in my paper on the phrase yathādhamma patikaroti: "Did King Ajātasattu Confess to the Buddha, and did the Buddha Forgive Him?" Journal of Buddhist Ethics. Vol 15. I'm grateful to Prof Gombrich for sending me a copy of his (hard to find) paper.
- I will use Princeton University's WordNet for convenience, and the online etymological dictionary.
- The four acceptance vows are: "With loyalty to my teachers I accept this ordination/ In harmony with friends and brethren I accept this ordination/ For the benefit of all beings I accept this ordination/ For the sake of enlightenment I accept this ordination".
- Sangharakshita. A Flame in the Darkness : the Life and Sayings of Anagārika Dharmapala. Tiratna Grantha Mala, 1980. This book is largely based on editorials written by Sangharakshita for the Mahābodhi Society Journal in the 1950's. Dharmapala's movement was subsequently labelled "Protestant Buddhism" by Gananath Obeyesekere. Ironically Dharmapala took the upasampadā shortly before his death in 1933.
I've noticed that some monks refer to themselves as "Bhante" (the third person vocative of the honorific pronoun). Bhante is what lay people call monks. It's kind of ridiculous for a monk to refer to themselves this way. Certainly it's bad Pāḷi grammar to use it as a title.