fad vs trend

fad

noun
  • A phenomenon that becomes popular for a very short time. 

trend

noun
  • A tendency. 

  • The lower end of the shank of an anchor, being the same distance on the shank from the throat that the arm measures from the throat to the bill. 

  • A line drawn on a graph that approximates the trend of a number of disparate points. 

  • The angle made by the line of a vessel's keel and the direction of the anchor cable, when she is swinging at anchor. 

  • An inclination in a particular direction. 

  • A fad or fashion style. 

verb
  • To have a particular direction; to run; to stretch; to tend. 

  • To cause to turn; to bend. 

  • To be the subject of a trend; to be currently popular, relevant or interesting. 

  • To cleanse or clean (something, usually wool). 

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