alpha-omega
nounUK /ˌælfə ˈəʊmɪɡə/
US /ˌælfə ˈoʊmɪɡə/
The very beginning and the very end of something.
The teacher said reading is the alpha-omega of learning.
OTHER MEANINGS
2. The first and last letters of the Greek alphabet.
Alpha and omega are the first and last letters of the Greek alphabet.
3. God as the eternal beginning and end in Christian tradition.
The prayer called God the alpha and omega.
4. The most important or essential part of something.
Trust is the alpha-omega of a good friendship.