fluctuation vs quiver

fluctuation

noun
  • A wavering; unsteadiness. 

  • In medicine, a wave-like motion or undulation of a fluid in a natural or abnormal cavity (e.g. pus in an abscess), which is felt during palpation or percussion. 

  • A motion like that of waves; a moving in this and that direction. 

quiver

noun
  • A multidigraph. 

  • A ready storage location for figurative tools or weapons. 

  • A container for arrows, crossbow bolts or darts, such as those fired from a bow, crossbow or blowgun. 

verb
  • To shake or move with slight and tremulous motion. 

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