A term used to refer to men attracted to men; sometimes used generically to refer to lesbians and bisexuals of both sexes as well.
One who has significant sexual and romantic attractions primarily to members of same sex (as oneself) often refers to only gay men, others use term to refer to gay men and lesbian women.
The word "Gay" has been used in the English language for hundreds of years meaning happy and exuberant. But it was only after the homosexual community began using it as a descriptive code to identify other members of their community did its meaning change. Officially, that date can be identified as 1953 when the meaning switched.