Internal radar instinct for detecting who is, or is not, gay.

The ability of gays to tell if others are gay, even when they are in the closet. The biggest give away is eye contact. Straight men only make eye contact when they are preparing to fight. The biggest give away for lesbians is sensible shoes.

an online dating service for gay men. If you decide to meet anyone from the website, be sure to take all the necessary steps to protect your safety.

Gay radar, the sense by which queers identify other queers. (RS)

The uncanny sensory perception that lesbians and gays have of detecting other gay people in their midst.

Slang for the ability to identify a gay person by sight.

The uncanny and seemingly innate ability lesbians and gay men tend to have to recognize and detect one another; from gay and radar.