BUMP, noun [Latin bombus, and Eng. pomp., from swelling, thrusting out.]
1. A swelling or protuberance.
2. A thump; a heavy blow.
BUMP, verb intransitive To make a loud, heavy or hollow noise, as the bittern. It is also written boom.
BUMP, verb transitive To strike as with or against any thing large or solid, as to bump the head against a wall; to thump.