Green’s Dictionary of Slang

1. to have a good time.

1924		Rosa Henderson ‘The Basement Blues’ 🎵 He don’t, he can’t / Hang round with dicty cats / Don’t go gay-cattin’ / ’Round in Buffet Flats.
1928		Blind Lemon jefferson ‘Maltese Cat Blues’ 🎵 I went gay cattin’ last night / An’ my gal, she threw a party for me.
1946		Mezzrow & Wolfe Really the Blues 215: I wasn’t working then, and didn’t have much money to gaycat with.
2001		N. Tosches Where Dead Voices Gather (ms.) 256: Papa Charlie Jackson had sung of ‘Gay Cattin’,’ of living high and cool and hip, in 1926.

2. to loiter and chat (in the street).

1988

(con. 1930s) C.E. Lincoln The Avenue, Clayton City (1996) 2: There really wasn’t much to do [...] except [...] to sit on the hard benches around the wall gay-catting and drinking pop.