Actually my apple dictionary still has that definition listed for my mac.
gay |gā| adjective ( gayer , gayest )
1 (of a person, esp. a man) homosexual: that friend of yours, is he gay?
• relating to or used by homosexuals: feminist, black, and gay perspectives.
2 lighthearted and carefree: Nan had a gay disposition and a very pretty face.
• brightly colored; showy; brilliant: a gay profusion of purple and pink sweet peas.
3 informal, often offensive foolish, stupid, or unimpressive: making students wait for the light is kind of a gay rule.
Not that I'm really all that concerned about it.