I. noun 1. the first letter of the Greek alphabet ( Α, α), transliterated as ‘a’. 2. [as modifier] — denoting the first of a series of items or categories, e.g. forms of a chemical compound • the α and β chains of haemoglobin.
(Brit.) a first-class mark given for an examination paper or piece of school or college work
• he had been awarded alpha double plus.
4. [as modifier] —
[Sociology] denoting the dominant animal or human in a particular group
• the pack is a tightly knit, highly organized group, led by an alpha wolf.
See also alpha male.
5. [as modifier] —
‹informal› denoting a person who has a dominant role or position within a particular sphere
• take turns cooking for each other if one of you is too much of an alpha chef.
6. short for alpha test. 7. ( Alpha) [followed by Latin genitive] —
[Astronomy] the first (typically the brightest) star in a constellation
• Alpha Orionis.
8. [as modifier] — relating to alpha decay or alpha particles • an alpha emitter.
9. a code word representing the letter A, used in radio communication. II. symbol 1. ( α) — a plane angle. 2. ( α) — angular acceleration. 3. ( α) —
[Astronomy] right ascension.
III. phrases alpha and omega a. the beginning and the end (used by Christians as a title for Jesus). b. the essence or most important features. • collective bargaining is seen as the alpha and omega of trade unionism.
– origin via Latin from Greek.