1. [mid-19C] (UK tramp) the tongue.
2. [mid-19C] the face or expression.
3. [mid-19C] language.
4. [late 19C+] (orig. US Und.) speech, impudent talk.
5. [20C+] (US black, also gibbs, jibbs, jibs) the mouth [dial. jib, the underlip; thus the mouth].
6. [1950s–60s] (US black) a tooth; usu. in pl., jibs.
see diarrhea of the mouth under diarrhoea n.
[1950s+] (US black) to talk wildly, out of control, in a panicky, unrestrained manner.
[2000s] (UK black) to speak in such a manner as to provoke a fight.
[1910s–60s] a talkative person.
[late 18C–19C] to look miserable, lit. to ‘hang one’s underlip’.
[1960s+] to chatter aimlessly.
[1930s–40s] (US black) to talk unrestrainedly.