Hapax legomenon

A hapax legomenon (pl. hapax legomena, though sometimes called hapaxes for short) is a word that occurs only once in the corpus of a language. (Occurrence in a dictionary that cites the occurrence in the corpus does not count.) Some of these are misspellings; others are real words that are rare enough that they only got used once. If a word is used twice it is a dis legomenon, thrice tris legomenon. Beyond tetrakis legomenon, a word isn't rare enough to call it that.

Some examples:

• "Nortelrye" is a word for "education" found only in Chaucer.
• "autoguos" (αυτογυος) is an ancient Greek word for a plow, found only in Hesiod, whose precise meaning is obscure

The word is also used more loosely (and therefore not quite correctly) to mean a word which occurs once in a given work, or once in a given author's work. Thus honorificabilitudinitatibus, occurring once in Shakespeare's plays, has been called a hapax legomenon, even though it does occur (exceedingly rarely) in other English works.

The term in its loose usage is popular among Bible scholars, who take the number of hapaxes in a putative author's corpus as an indication of his vocabulary and thereby argue for or against attribution. The identification of a word as a hapax by these authors means only that it occurs once in the Bible or yet more narrowly, once in the New Testament, rather than indicating that it occurs once in a language.