muzzle

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

• noun The forward, projecting part of the head of certain animals, such as dogs, including the mouth, nose, and jaws; the snout.
• noun A device that is fitted over an animal's snout, often used to prevent biting or eating.
• noun The forward, discharging end of the barrel of a firearm.
• noun A restraint on free movement or expression.
• transitive verb To put a muzzle on (an animal).
• transitive verb To restrain from expression.

from The Century Dictionary.

• noun A workman's name for a covering of many folds of flannel cloth tied over the nose and mouth of one who is engaged in removing bleaching-powder from the chambers in which it is made, and in packing it, to afford protection from the chlorin gas and the fine dust suspended in the air. A sponge moistened with water is sometimes used in the same way.
• noun A chain clevis or shackle.
• To bind or confine the mouth of in order to prevent biting or eating.
• Figuratively, to gag; silence.
• . To mask.
• . To fondle with the closed mouth; nuzzle.
• To grub up with the snout, as swine do.
• To handle or pull about.
• To bring the muzzle or mouth near.
• To drink to excess; guzzle.
• To loiter; trifle; skulk.
• noun The projecting jaws and nose of an animal, as an ox or a dog; the snout.
• noun The mouth of a thing; the end for entrance or discharge: applied chiefly to the end of a tube, as the open end of a gun or pistol.
• noun Anything which prevents an animal from biting, as a strap around the jaws, or a sort of cage, as of wire, into which the muzzle (def. 1) is inserted.
• noun In armor, an openwork, covering for the nose, used for the defense of the horse, and forming part of the bards in the fifteenth and sixteenth centuries.
• noun A piece of the forward end of the plow-beam by which the traces are attached: same as bridle, 5.
• noun Muzzle-energy, the energy of a shot when it leaves the muzzle of a gun, expressed by the formula = foot-tons of energy, w representing the weight of shot in pounds and v the velocity in feet per second.

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

• transitive verb To bind the mouth of; to fasten the mouth of, so as to prevent biting or eating; hence, figuratively, to bind; to sheathe; to restrain from speech or action.
• transitive verb obsolete To fondle with the closed mouth.
• intransitive verb To bring the mouth or muzzle near.
• noun The projecting mouth and nose of a quadruped, as of a horse; a snout.
• noun The mouth of a thing; the end for entrance or discharge.
• noun A fastening or covering (as a band or cage) for the mouth of an animal, to prevent eating or vicious biting.
• noun (Gun.) See Dispart, n., 2.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The protruding part of many animal's head which includes nose, mouth and jaws; snout
• noun The mouth or the end for entrance or discharge of a gun, pistol etc., that the bullet emerges from as opposed to the breech.
• noun A device used to prevent animal from biting or eating, which is worn on its snout.
• noun A piece of the forward end of the plow-beam by which the traces are attached; bridle
• noun obsolete, historical An openwork covering for the nose, used for the defense of the horse, and forming part of the bards in the 15th and 16th centuries.
• verb transitive To bind or confine animal's mouth by putting a muzzle, as to prevent it from eating or biting.
• verb transitive, figuratively To restrain (from speaking, expressing opinion or acting); gag, silence.
• verb transitive, obsolete To veil, mask, muffle.
• verb transitive, obsolete To fondle with the closed mouth; to nuzzle.
• verb intransitive To bring the muzzle or mouth near.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb fit with a muzzle
• verb prevent from speaking out
• verb tie a gag around someone's mouth in order to silence them
• noun the open circular discharging end of a gun
• noun a leather or wire restraint that fits over an animal's snout (especially a dog's nose and jaws) and prevents it from eating or biting
• noun restraint put into a person's mouth to prevent speaking or shouting
• noun forward projecting part of the head of certain animals; includes the jaws and nose