"a mouthful, lump," late 14c., probably from Old French gobe "mouthful, lump," related to gober "gulp, swallow down," probably from Gaulish *gobbo- (cf. Irish gob "mouth," Gaelic gob "beak"). This Celtic source also seems to be root of gob "mouth" (mid-16c.), which is the first element in gob-stopper "a kind of large hard candy" (1928).
The mouth •Chiefly British use
[1550+; fr Irish]
A US Navy sailor; swabby
[1915+; perhaps fr earlier British gabby, ''coast guard; quarterdeckman,'' of unknown origin]