carol vs hum

carol

verb
  • To sing (a song) cheerfully. 

  • To sing carols; especially to sing Christmas carols in a group. 

  • To praise or celebrate in song. 

  • To sing in a joyful manner. 

  • To participate in a carol (a round dance accompanied by singing). 

noun
  • A (usually traditional) religious or secular song sung at Christmastime. 

  • A round dance accompanied by singing. 

  • A ballad or song of joy. 

hum

verb
  • To express by humming. 

  • To produce low sounds which blend continuously 

  • To reek, smell bad. 

  • To make a sound from the vocal chords without pronouncing any real words, with one's lips closed. 

  • To drone like certain insects naturally do in motion, or sounding similarly 

  • To buzz, be busily active like a beehive 

intj
  • Synonym of um: a noise indicating doubt, uncertainty, &c. 

  • Synonym of hmm: a noise indicating thought, consideration, &c. 

noun
  • Unpleasant odour. 

  • A phenomenon, or collection of phenomena, involving widespread reports of a persistent and invasive low-frequency humming, rumbling, or droning noise not audible to all people. 

  • Busy activity, like the buzz of a beehive. 

  • A hummed tune, i.e. created orally with lips closed. 

  • An often indistinct sound resembling human humming. 

How often have the words carol and hum occurred in a corpus of books? (source: Google Ngram Viewer )