fibrillate vs flounder

fibrillate

verb
  • To make rapid irregular movements. 

flounder

verb
  • To make clumsy attempts to move or regain one's balance. 

  • To flop around as a fish out of water. 

  • To be in serious difficulty. 

  • He gave a good speech, but floundered when audience members asked questions he could not answer well. 

  • To act clumsily or confused; to struggle or be flustered. 

noun
  • A bootmaker's tool for crimping boot fronts. 

  • A European species of flatfish having dull brown colouring with reddish-brown blotches; fluke, European flounder, Platichthys flesus. 

  • Any of various flatfish of the family Pleuronectidae or Bothidae. 

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