Defn: To make a loud, heavy, or hollow noise, as the bittern; to
boom.
As a bittern bumps within a reed. Dryden.

BUMP
Bump, n.

Defn: The noise made by the bittern.

BUMPER Bum"per, n. Etym: [A corruption of bumbard, bombard, a large drinking vessel.]

1. A cup or glass filled to the brim, or till the liquor runs over, particularly in drinking a health or toast. He frothed his bumpers to the brim. Tennyson.

2. A covered house at a theater, etc., in honor of some favorite performer. [Cant]

BUMPER
Bump"er, n.

1. That which bumps or causes a bump.

2. Anything which resists or deadens a bump or shock; a buffer.

BUMPKIN Bump"kin, n. Etym: [The same word as bumkin, which Cotgrave defines thus: "Bumkin, Fr. chicambault, the luffe-block, a long and thick piece of wood, whereunto the fore-sayle and sprit-sayle are fastened, when a ship goes by the winde." Hence, a clumsy man may easily have been compared to such a block of wood; cf. OD. boomken a little tree. See Boom a pole.]