Meaning of ALPHA in English

n. 1 the first letter of the Greek alphabet (A). 2 a first-class mark given for a piece of work or in an examination. 3 Astron. the chief star in a constellation. alpha and omega the beginning and the end; the most important features. alpha particle (or ray) a helium nucleus emitted by a radioactive substance, orig. regarded as a ray.

[ ME f. L f. Gk ]

Concise Oxford English dictionary.      Краткий оксфордский словарь английского языка.