According to urban dictionary
Your teeth, but can be used to refer to any of the general visible mouth area.
"Crack you in the jibs, if you ain't careful" , "You better watch your mouth 'cause you about to get busted in the jibs"
teeth gums mouth lips or front-teeth.
jaws,jaw,mouth and/or using any one of them excessively.
"I met this chick at a party last night that I thought was hot,but all she wanted to do was run her jibs about her ex-boyfriend,I was SO not into that."
those little bits of skin you see just peeking out from under a pair of daisy dukes on a tight posterior.
dang ma, i can see your jibs.