Bump , n. The noise made by the bittern.

Bump , v. i. [See Boom to roar.] To make a loud, heavy, or hollow noise, as the bittern; to boom.

As a bittern bumps within a reed.Dryden. Dryden.

Bump (?), v. t. [imp. & p. p. Bumped (?); p. pr. & vb. n.Bumping.] [Cf. W. pwmp round mass, pwmpiaw to thump, bang, and E. bum, v. i., boom to roar.] To strike, as with or against anything large or solid; to thump; as, to bump the head against a wall.

Bump (?), n. [From Bump to strike, to thump.]

1. A thump; a heavy blow.

2. A swelling or prominence, resulting from a bump or blow; a protuberance.

"It had upon its brow A bump as big as a young cockerels stone. Shak.

3. (Phren.) One of the protuberances on the cranium which are associated with distinct faculties or affections of the mind; as, the bump of "veneration;" the bump of "acquisitiveness." [Colloq.]

4. The act of striking the stern of the boat in advance with the prow of the boat following. [Eng.]

Bump , v. i. To come in violent contact with something; to thump. "Bumping and jumping." Southey.

-- Webster's unabridged 1913