hum vs plop

hum

verb
  • To produce low sounds which blend continuously 

  • To express by humming. 

  • 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. 

plop

verb
  • To make the sound of an object dropping into a body of liquid. 

  • To defecate. 

  • To land heavily or loosely. 

intj
  • Indicating the sound of something plopping. 

noun
  • A sound or action like liquid hitting a hard surface, or an object falling into a body of water. 

  • Excrement. 

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