Hammer n. : An instrument for driving nails, beating metals, and the like, consisting of a head, usually of steel or iron, fixed crosswise to a handle.

Hammer n. : Something which in firm or action resembles the common hammer

Hammer n. : That part of a clock which strikes upon the bell to indicate the hour.

Hammer n. : The padded mallet of a piano, which strikes the wires, to produce the tones.

Hammer n. : The malleus.

Hammer n. : That part of a gunlock which strikes the percussion cap, or firing pin; the cock; formerly, however, a piece of steel covering the pan of a flintlock musket and struck by the flint of the cock to ignite the priming.

Hammer n. : Also, a person of thing that smites or shatters; as, St. Augustine was the hammer of heresies.

Hammer v. t. : To beat with a hammer; to beat with heavy blows; as, to hammer iron.

Hammer v. t. : To form or forge with a hammer; to shape by beating.

Hammer v. t. : To form in the mind; to shape by hard intellectual labor; -- usually with out.

Hammer v. i. : To be busy forming anything; to labor hard as if shaping something with a hammer.

Hammer v. i. : To strike repeated blows, literally or figuratively.

Example:
How big of a problem is an exposed Hammer on a small revolver for conceal carry?

Taxonomy
hammer, sledgehammer, stones, mass, hammer head, energy, target increases, free encyclopedia, Mechanically, Designs, War hammers, blacksmithing, hand tools, kinetic energy, the user, claw hammer, Tools, shape.

Defination from the web:
hammer is a basic tool of many professions, and can also be used as a weapon. ... In the hatchet the hammer head is secondary to the cutting edge of the tool. As the impact between steel hammer heads and the objects being hit can, and does, create sparks, which in some industries ...