Meaning

noun the open circular discharging end of a gun

noun forward projecting part of the head of certain animals; includes the jaws and nose

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

originFrom earlier muzle, musle, mousle, mussel, mozell, from Middle English mosel, from Old French musel, museau, muzeau (modern French museau), from Late Latin mūsus (“snout”), probably expressive of the shape of protruded lips and/or influenced by Latin mūgīre (“to moo, bellow”). Doublet of museau. Displaced native Middle English kevel from Old English cæfl (“gag, bit, muzzle”), see English cavel.

Etymology from Wiktionary, CC BY-SA 3.0