alpha and omega Definition

alpha
noun

1. The first letter of the Greek alphabet.
(Brit)
2a. A mark given to an exam paper or other piece of work that denotes a first class grade;
(Brit)
2b. A mark above or below alpha respectively.

Form: alpha plus
Form: alpha minus
3. astron.
The brightest star in a constellation.
4. communications.
In the NATO alphabet: the word used to denote the letter ‘A'.
Form: Alpha
5a. chem.
Designating one of two or more isomeric forms of a compound;
5b. zool.
Referring to the most dominant member of a hierarchical group.
Example: That gorilla is the alpha female

Idiom: alpha and omega

The beginning and the end.

Etymology: 14c: Greek, from Hebrew and Phoenician aleph an ox or a leader, the original hieroglyph being in the form of an ox's head.