Part(s) of speech: Indeclinable letter (Noun)
Definition: alpha; the first letter of the Greek alphabet.
From: Public Domain Greek-English lexicon by John Jeffrey Dodson (2010)
Derivation: of Hebrew origin;
Definition: the first letter of the alphabet; figuratively, only (from its use as a numeral) the first:
From: Strong's Greek Dictionary by James Strong (1890)
Α, α, ἄλφα (q.v.), τό, indecl.,
alpha, the first letter of the Greek alphabet. As a numeral, αʹ = 1, α͵ = 1000. As a prefix, it appears to have at least two and perhaps three distinct senses:
1. ἀ- (before a vowel, ἀν-) negative, as in ἄ-γνωστος, ἄ-δικος.
2. ἀ-, ἁ- copulative, indicating community and fellowship, as in ἁ-πλοῦς, ἀ-κολουθέω, ἀ-δελφός.
3. An intensive force (LS, s. α), as in ἀ-τενίζω is sometimes assumed (but v. Boisacq, s.v.).
From: Abbott-Smith, George, "A Manual Greek-English Lexicon of the Greek New Testament", 1922. Public Domain.