Meaning of ALPHA in English

[al.pha] n [ME, fr. L, fr. Gk, of Sem origin; akin to Heb aleph aleph] (13c) 1: the 1st letter of the Greek alphabet

2: something that is first: beginning

3: alpha wave

4: alpha particle

[2]alpha adj (1863) 1: closest in the structure of an organic molecule to a particular group or atom "alpha-substitution"

2: socially dominant esp. in a group of animals

3: alphabetic

Merriam-Webster English vocab.      Английский словарь Merriam Webster.