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.

Phrases and idioms:

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.

Etymology: ME f. L f. Gk

Oxford English vocab.      Оксфордский английский словарь.