n. 25B6; noun
a protuberance can cause drag : BUMP, lump, knob, projection, protrusion, sticking-out bit, prominence, swelling, eminence, outcrop, outgrowth, jut, jag, snag; ledge, shelf, ridge; informal sticky-out bit.
the protuberance of the incisors : STICKING OUT, jutting, projection, obtrusion, prominence; swelling, bulging.