fluctuate vs hover

fluctuate

verb
  • To be irresolute; to waver. 

  • To cause to vary irregularly. 

  • To vary irregularly; to swing. 

  • To undulate. 

hover

verb
  • To be indecisive or uncertain; to vacillate, to waver. 

  • To keep (something, such as an aircraft) in a stationary state in the air. 

  • Sometimes followed by over: to hang around or linger in a place, especially in an uncertain manner. 

  • Of a bird: to shelter (chicks) under its body and wings; (by extension) of a thing: to cover or surround (something). 

  • To remain stationary or float in the air. 

  • Chiefly followed by over: to use a mouse or other device to place a cursor over something on a screen such as a hyperlink or icon without clicking, so as to produce a result (such as the appearance of a tooltip). 

  • To travel in a hovercraft as it moves above a water surface. 

noun
  • An act, or the state, of remaining stationary in the air or some other place. 

  • A flock of birds fluttering in the air in one place. 

  • A cover; a protection; a shelter; specifically, an overhanging bank or stone under which fish can shelter; also, a shelter for hens brooding their eggs. 

  • An act, or the state, of being suspended; a suspension. 

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