hammer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A hand tool consisting of a handle with a head of metal or other heavy rigid material that is attached at a right angle, used for striking or pounding.
• noun A tool or device similar in function or action to this striking tool, as.
• noun The part of a gunlock that hits the primer or firing pin or explodes the percussion cap and causes the gun to fire.
• noun Music One of the padded wooden pieces of a piano that strikes the strings.
• noun A part of an apparatus that strikes a gong or bell, as in a clock.
• noun Sports A metal ball weighing 16 pounds (7.2 kilograms) and having a long wire or wooden handle by which it is thrown for distance in track-and-field competition.
• noun A small mallet used by auctioneers.
• intransitive verb To hit, especially repeatedly, with a hammer; pound. synonym: beat.
• intransitive verb To strike forcefully and repeatedly.
• intransitive verb To assault with military force.
• intransitive verb To beat into a shape with a hammer or similar tool.
• intransitive verb To accomplish or produce with difficulty or effort. Often used with out.
• intransitive verb To put together, fasten, or seal, particularly with nails, by hammering.
• intransitive verb To force upon (someone) by constant repetition.
• intransitive verb To cause harm, loss, or difficulty to (someone), especially repeatedly.
• intransitive verb To defeat soundly.
• intransitive verb To attack verbally.
• intransitive verb To deal repeated blows with or as if with a hammer; pummel.
• intransitive verb To undergo beating in the manner of a hammer.
• intransitive verb Informal To keep at something continuously. Often used with away:
• idiom (under the hammer) For sale at an auction.

from The Century Dictionary.

• noun A yellowhammer or bunting. As used in the following passage the meaning of the word is uncertain. See etymology.
• To stammer.
• noun In athletics, a 16-pound weight (or a 12-pound weight for school-boys), attached by ball-bearing to a wire handle, which competitors, standing in a marked circle, endeavor to throw as far as possible. The old-fashioned hammer had an ordinary stiff wooden handle.
• To declare (a member) to be in default, after notice by hammering three times on the rostrum.
• To beat down or depress (price or the market); bear.
• To make a knocking noise, as a steam-pipe when steam is let on and a water-hammer is produced. See water-hammer, 2.
• To beat or drive with or as if with a hammer; pound; beat: as, to hammer iron or steel; to hammer one with the fist.
• To fasten with a hammer by nailing or otherwise; construct by the use of the hammer.
• To form or forge with a hammer; shape by beating: often with out.
• To work upon in the mind; contrive by intellectual labor; excogitate: usually with out: as, to hammer out a scheme.
• To strike something repeatedly with or as if with a hammer.
• To work industriously or persistently; be very busy; labor in contrivance: as, to be hammering away at an invention.
• To be working or in agitation; keep up an excited action or state of feeling.
• noun An instrument consisting of a solid head, usually of metal, but sometimes of wood or of stone, set crosswise to the handle, used for beating metals, driving nails or spikes, dressing or breaking stones, etc.; hence, a machine in which a heavy block of metal is used for such a purpose. See steam-hammer, tilt-hammer, trip-hammer.
• noun Something which resembles the common hammer in form, action, or use.
• noun A door-knocker.
• noun In anatomy, the malleus.
• noun The head of a sphyrnid or hammer-headed shark.
• noun Figuratively, an aggressive and destructive foe: as, a hammer of heretics (Latin malleus hœreticorum).
• noun Same as fylfot.
• noun A pendent ornament, usually of silver, found among relics of the prehistoric iron age in the north of Europe. It has somewhat the shape of a mallet, and is undoubtedly intended to represent a hammer as weapon or utensil.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To beat with a hammer; to beat with heavy blows.
• transitive verb To form or forge with a hammer; to shape by beating.
• transitive verb To form in the mind; to shape by hard intellectual labor; -- usually with out.
• intransitive verb To be busy forming anything; to labor hard as if shaping something with a hammer.