Etymology: < Middle French musel, muzel mouth or snout of an animal (early 13th cent. in Old French; Middle French, French museau ), mouth or face of a person (early 13th cent.), guard for an animal's mouth (mid 13th cent.), veil worn over the lower part of a woman's face (mid 13th cent.), opening of a firearm (1521 as muzeau ), probably < post-classical Latin musellum guard for an animal's mouth (1252 in a British source), animal's mouth, snout (from late 13th cent. in British and continental sources) < post-classical Latin musus , musum muzzle, snout (784; a1235 in a British source; see below) + -ellum -ellum suffix; compare -le suffix 2. As post-classical Latin musellum is apparently first recorded slightly later than Old French musel , it is possible that the French word derives independently either < post-classical Latin musus , musum + Old French -el -el suffix², or < its (unattested) Old French reflex *mus (compare Old Occitan mus face (13th cent.: see note below)) or the derivative muse (feminine) mouth, muzzle (13th cent.) + -el -el suffix².Postclassical Latin musus or musum is of uncertain origin: it has been suggested that it may be an expressive formation arising from the shape of the lips and mouth in pronouncing the first syllable; perhaps compare classical Latin mūgīre (see mugient adj.). Also derived < post-classical Latin musus , musum are: Old Occitan, Occitan mus face (12th cent.), Spanish mus , Italian muso (1300–13); see also muse v., and etymological note at that entry. Middle French mouse mouth, muzzle (1442) probably represents a variant of muse , influenced by mouwe (see mow n.²). Attempts of earlier scholars to connect Old French musel , muse , and cognates with Old Occitan morsel jaw (a specific sense development of a cognate of Old French morsel morsel n.), and hence to derive both groups of words ultimately from classical Latin morsus (see morsel n.), have not met with general acceptance. Occasional spellings musel for morsel morsel n. in Anglo-Norman, and occasional English spellings in -r- for muzzle n.¹ (see forms list above), probably result from confusion of the two words.

Etymology: Ultimately < German Mosel Moselle n., perhaps via the corresponding Dutch form Moezel, or perhaps altered humorously after muzzle n.¹ or perhaps muzzle v.² Compare Mossel , variant of Moselle n. N.E.D. (1908) gives the pronunciation as (mɒ·z'l) /ˈmʌz(ə)l/.

Etymology: Probably alteration of muzzled adj.² (see etymological discussion at that entry).

Etymology: < muzzle n.¹ Compare Middle French, French museler to cover the mouth of an animal with a muzzle (late 14th cent.). With senses 7 and 8 compare nuzzle v.¹

Etymology: Perhaps < muzz v. + -le suffix 3. See further etymological note s.v. muzzy adj.The following quot. may perhaps also illustrate this word, although the lack of other evidence before the late 18th cent. probably suggests that it is better explained as a figurative use of muzzle v.¹:a1643 W. Monson Naval Tracts iv, in A. Churchill & J. Churchill Coll. Voy. (1732) (modernized text) III. 397/2 Barbadoes and St. Christopher's..produce nothing but stinking tobacco... It has such a bewitching power over the takers, that all the ill which comes of it, they interpret as good to their bodies, and have no more power to leave it, than drunkards when they are muzzled in it.