a tool consisting of a solid head, usually of metal, set crosswise on a handle, used for beating metals, driving nails, etc.

any of various instruments or devices resembling this in form, action, or use, as a gavel, a mallet for playing the xylophone, or a lever that strikes the bell in a doorbell.

Firearms . the part of a lock that by its fall or action causes the discharge, as by exploding the percussion cap or striking the primer or firing pin; the cock.

one of the padded levers by which the strings of a piano are struck.

Track . a metal ball, usually weighing 16 lb. (7.3 kg), attached to a steel wire at the end of which is a grip, for throwing for distance in the hammer throw.

Anatomy . the malleus.

to beat or drive (a nail, peg, etc.) with a hammer.

to fasten by using hammer and nails; nail (often fol. by down, up, etc.)

We spent the day hammering up announcements on fences and trees.

to assemble or build with a hammer and nails (often fol. by together )

He hammered together a small crate.

to shape or ornament (metal or a metal object) by controlled and repeated blows of a hammer; beat out

to hammer brass; to hammer a brass bowl.

to form, construct, or make with or as if with a hammer; build by repeated, vigorous, or strenuous effort (often fol. by out or together )

to hammer out an agreement; to hammer together a plot.

to produce with or by force (often fol. by out )

to hammer out a tune on the piano; to hammer a home run.

to pound or hit forcefully

to hammer someone in the jaw.

to settle (a strong disagreement, argument, etc.); bring to an end, as by strenuous or repeated effort (usually fol. by out )

They hammered out their differences over a glass of beer.

to present (points in an argument, an idea, etc.) forcefully or compellingly; state strongly, aggressively, and effectively (often fol. by home ).

to impress (something) as if by hammer blows

You'll have to hammer the rules into his head.

British .

(in the London stock exchange) to dismiss (a person) from membership because of default.

to depress the price of (a stock).

to strike blows with or as if with a hammer.

to make persistent or laborious attempts to finish or perfect something (sometimes fol. by away )

He hammered away at his speech for days.

to reiterate; emphasize by repetition (often fol. by away )

The teacher hammered away at the multiplication tables.

under the hammer

for sale at public auction

The old estate and all its furnishings went under the hammer.

verb

bang , batter , bear down , clobber , defeat , drive , drub , fashion , forge , form , knock , make , pound , pummel , shape , strike , tap , thrash , trounce , wallop , whack , whomp , assail , assault , baste , belabor , buffet , smash , thresh , beat , beetle , hit , malleate , maul , mell , nail , punch , ram , reiterate , sledge , tack , tamp