Synonyms for Hum:

n.

back, blast away, atmospherics, blast, baton, articulation, beat out, arrange, bang out, accompany. bustling, whiz, lively, whir, sounds, burr, frenzy, peak, hectic, Grand Central Station, bumble, madhouse, busy season. rumor/word/legend has it that, not that I'm aware of, I would think/imagine/hope etc., it/that depends, maybe, I dare say, presumably, reportedly, perhaps. resonate, roar, resound, pulsate. groan, thud, growl, clunk, pitch. buzz (noun)
sing in an undertone, zoom, bum, whisper, murmur, sound, whir, vibrate, sing low, hum a tune, make a buzzing sound, sing without articulation, moan, purr, croon.
drone (noun)
buzz.
hum (noun)
humming, thrum, seethe, buzz.
murmur (noun)
humming, rumble, grumble.
rumble (noun)
buzz, chant, throb, clatter, beat, chatter, racket, reverberation, roll, grumble, thunder, thrum, drum, drone, rattle, rumble.
speed (noun)
zoom.

v.

buzz (verb)
whiz, reverberate.
drone (verb)
vibrate, chant.
hum (verb)
croon, throb, zoom, whisper, sing low, sound, bum, purr, whir, moan, drone, bumble, thrum, murmur.
murmur (verb)
growl.
operate (verb)
roll.
roll (verb)
rattle, roar, resound, drum.
rumble (verb)
reverberate.

Other synonyms:

clunk, presumably, busy season, whisper, Grand Central Station, murmur, burr, madhouse, resound, frenzy, croon, bustling, reportedly, hectic. perhaps, lively, thud, resonate, whiz, pulsate. purr, maybe. moan, sound, peak, growl. groan. pitch. whiz
whir.
Other relevant words:
baton, sing low, burr, back, clunk, whisper, humming, murmur, purr, pitch, bumble, resound, growl, resonate, pulsate, whiz, frenzy, zoom, bum, vibrate, articulation, maybe, presumably, seethe, thud, arrange, accompany, lively, whir, perhaps, peak, hectic, madhouse, atmospherics, sound, bustling, groan, sounds, blast, reportedly, moan, croon, roar.

Usage examples for hum

  1. " Hum yes- yes, my young friend. – The Border Boys Across the Frontier by Fremont B. Deering
  2. But once more alone, with only the hum of voices from the reception- room as company, she fell silent, and I could think of nothing to say. – Blindfolded by Earle Ashley Walcott
  3. Over their heads, behind their backs, the little brown bees would fly, singing their song:- Hum hum hum – Mother Stories by Maud Lindsay