Aha definition

Any of a group of natural or synthetic alpha hydroxy acids, including lactic acid and glycolic acid, found in fruit, sour milk, sugar cane, etc. and used in making cleansing creams and lotions that exfoliate the skin.

Alpha-hydroxy acid.

The definition of aha is something said to express surprise, understanding, or a discovery.

Used to express surprise, pleasure, or triumph.

Used to express triumph, surprise, pleasure, satisfaction, etc., often mixed with irony or mockery.

Initialism of alpha-hydroxy acid.