hum vs scat

hum

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

  • To produce low sounds which blend continuously 

  • To express by humming. 

  • To reek, smell bad. 

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

  • To buzz, be busily active like a beehive 

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. 

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

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

scat

verb
  • To sing an improvised melodic solo using nonsense syllables, often onomatopoeic or imitative of musical instruments. 

  • Here comes the principal; we'd better scat. 

  • To leave quickly. 

intj
  • An imperative demand to leave, often understood by speaker and listener as impertinent. 

  • Scat! Go on! Get out of here! 

noun
  • A tax; tribute. 

  • Animal excrement; droppings, dung. 

  • Coprophilia. 

  • Heroin. 

  • Any fish in the family Scatophagidae 

  • A land-tax paid in the Shetland Islands. 

  • A brisk shower of rain, driven by the wind. 

  • Scat singing. 

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