Fairly large, usually round breasts
that possess the quality of sitting un-usually high and very close together on a woman's chest, they are also commonly accompanied by very deep cleavage
Thus appearing to resemble a sort of boob
Perfect for tit fucking
and catching food that misses her mouth just the same.
Can be found on in many different body types, although if you see bib tits on a skinny girl they are most likely FAKE, but not always.
Person A: Man check out the bib tits on that one!
Person B: Wow! They could hold your cock
and a snack at the same time.