The word ‘gay’ was used in Middle English to describe something that is
attractive, showy, or merry (used to describe a person’s feelings). The sense ‘
homosexual’ is first used in 1950s, and the noun is first used in 1971. For a teen slang meaning, bad, stupid and foolish was first used in 2000s. However, this pejorative use is considered offensive by many people, especially
homosexuals.