(chiefly in plural or attributive) A homosexual, especially a male homosexual; see also lesbian.

Something which is bright or colorful, such as a picture or a flower.

An ornament, a knick-knack.

To make happy or cheerful.

To cause (something, e.g. AIDS) to be associated with homosexual people.

(possibly obsolete) Happy, joyful, and lively.

“The Gay Science”

Quick, fast.

(possibly obsolete) Festive, bright, or colourful.

“Pennsylvania Dutch include the plain folk and the gay folk.”

(possibly obsolete) Considerably, very.