Gob is also coarse slang for mouth in England

or spit, and gobbing is spitting. Not the Nine O'clock news did a take off of the TV soccer competition "Goal of the Month" showing soccer players spitting (as they frequently do), and called it "Gob of the Month".

French has the words "gober" to swallow whole, and "gobemouche" = literally a fly swallower, someone who stands around with their mouth open. My POD gives gob (spit) from the French goube= a mouthful.

And gobble comes from the same root.

Rod