What does bomb mean?
The definition of bomb
Bomb, n.
Etym: [F. bombe bombshell, fr. L. bombus a humming or buzzing noise, Gr. .]

1 A great noise; a hollow sound. [Obs.] A pillar of iron . . . which if you had struck, would make . . . a great bomb in the chamber beneath. Bacon.
2 (Mil.)
A shell; esp. a spherical shell, like those fired from mortars. See Shell.
3 A bomb ketch. Bomb chest (Mil.), a chest filled with bombs, or only with gunpowder, placed under ground, to cause destruction by its explosion.

— Bomb ketch, Bomb vessel (Naut.), a small ketch or vessel, very strongly built, on which mortars are mounted to be used in naval bombardments; — called also mortar vessel.
— Bomb lance, a lance or harpoon with an explosive head, used in whale fishing.
— Volcanic bomb, a mass of lava of a spherical or pear shape. “I noticed volcanic bombs.” Darwin.

Bomb, v. t.
To bombard. [Obs.] Prior.
Bomb, v. i.
Etym: [Cf. Boom.]

To sound; to boom; to make a humming or buzzing sound. [Obs.] B. Jonson.