Green’s Dictionary of Slang

bird n.3

1. [late 19C+] (mainly US) the penis; thus jerk one’s bird, to masturbate; get one’s bird in a splint, to get into (painful) difficulties; gobble someone’s bird, to fellate; how’s your bird? a phrase of greeting.

2. [1960s–70s] (US) the vagina.

3. [1970s] (US gay) fellatio.

In compounds

birdbath (n.)

[1970s] the vagina.

bird circuit (n.)

see separate entry.

bird taker (n.)

1. [1930s–40s] a sodomite.

2. [1970s+] (US gay) a male prostitute.

In phrases

bird in a gilded cage (n.)

[1970s+] (US gay) a man’s crotch in a pair of expensive trousers.

cop a bird (v.)

[1930s–40s] (US) usu. of a prostitute, to fellate.