noun

• (slang, derogatory, by extension) A person's mouth.
• (firearms) The mouth or the end for entrance or discharge of a gun, pistol etc., that the bullet emerges from.
• (chiefly Scotland) A piece of the forward end of the plow-beam by which the traces are attached.
• (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 an animal's mouth by putting a muzzle, as to prevent it from eating or biting.
  "Thou shalt not muzzle the ox when he treadeth out the corn."
• (transitive, figuratively) To restrain (from speaking, expressing opinion or acting); to gag; to silence; to censor.
  "Those who want to muzzle everyone else are likely nothing less than pseudovirtuous."
• (transitive, obsolete) To veil, mask, muffle.
• (transitive, obsolete) To fondle with the closed mouth; to nuzzle.
  "Venus her self would sit Muzzling and Gazing them in the Eyes"