Abarim Publications' online Biblical Greek Dictionary
A loose letter α (alpha) in the Greek text of the Bible is always a form of the relative pronoun ος (hos), namely the neutral plural form of either the nominal or accusative. It would mean "who/which/that" (in plural). For instance, the English versions of Revelation 1:9 speaks three times of "the things", where in Greek only the letter α appears.
Jesus famously called Himself the Alpha and Omega, but this may not refer to simply the first and the last letters of the Greek alphabet. See our article on the relative pronouns for more.
A prefixed α can represent one of three functions, as there are really three different prefixes that look like the same α- (a-). They are different because these three a-'s are remnants of different words and mean different things:
- The most familiar α- (a-) is the negating α- (a-). It survives into modern English and is probably a leftover from ανευ (aneu), meaning without, or ατερ (ater), meaning apart from. When this α- (a-) is tied to a word that starts with a vowel, it comes with an added ν (n).
- The intensifying α- (a-) probably stems from αγαν (agan), meaning very much. An example of the use of this prefix is in the verb ατενιζω (atenizo), meaning to look intently, from the verb τεινω (teino), meaning to stretch or strain.
- The collecting α- (a-) comes from αμα (hama), meaning together with. An example of the use of this prefix is in the noun αδελφος (adelphos), meaning brother, from the noun δελφυς (delphus), meaning womb.