Etymology: Partly < Middle French, French murmure indistinct expression of feeling by a number of people (c1170 in Old French), subdued expression of discontent (c1200), muted noise (c1230), sound of a light breeze (1555), respiratory murmur (1819 in passage translated in quot. 1821 at sense 5) < murmurer murmur v.; and partly < its ultimate etymon classical Latin murmur a low, continuous sound, a subdued or indistinct utterance, such an utterance indicative of anger or resentment, a reduplicated imitative formation (see murmur v. for possible cognates). Compare Anglo-Norman murmure, murmur trouble, disturbance.Compare post-classical Latin murmurium (6th cent.), Old Occitan murmuri (c1235), Spanish murmurio (c1240; c1236 as mormorio), Portuguese murmúrio (17th cent.; 15th cent. as murmuro, mormuuriio, 14th cent. as murmuiro, 13th cent. as mormoyro), Italian mormorìo (c1300).

Etymology: < Anglo-Norman murmurer to complain, grumble, Middle French murmurer to complain, grumble (first half of the 12th cent. in Old French), to utter in a subdued voice (1176), to talk in a subdued voice (13th cent.), to make a low continuous sound (c1200) and its etymon classical Latin murmurāre to make a low continuous sound, to speak in an indistinct voice, to utter in subdued tones, to grumble, complain < murmur murmur n. Compare Spanish murmurar, mormurar (1220–50), Portuguese murmurar (late 13th cent.), Italian mormorare (a1292). Perhaps ultimately < the same base as classical Latin murmur and murmurāre are: Middle Dutch murmuren, murmeren (Dutch murmelen), Middle Low German murmelen, murmulen, murmeren, Old High German murmurōn, murmulōn to murmur (Middle High German murmern, murmeln, German murmeln), ancient Greek μορμύρειν to boil up (as the waves), Sanskrit marmara (adjective and noun) rustling, Lithuanian murmėti to mutter, murmur, babble, murmuliuoti to boil, mutter, murmur.