Green’s Dictionary of Slang

1. (US) clothes.

1910

O. Johnson Varmint 349: ‘Like my jibs?’ said Stover, throwing back his coat.

2. (US black) the buttocks.

1972

D. Claerbaut Black Jargon in White America 70: jibs n. […] 2. buttocks.

3. (US) a woman’s breasts.

1986

in Playboy Apr. 20: Breasts [...] Jibs [HDAS].