droop vs swab

droop

verb
  • To allow to droop or sink. 

  • To lose all energy, enthusiasm or happiness; to flag. 

  • To slowly become limp; to bend gradually. 

  • To proceed downward, or toward a close; to decline. 

  • To hang downward; to sag. 

noun
  • A condition or posture of drooping. 

  • A hinged portion of the leading edge of an aeroplane's wing, which swivels downward to increase lift during takeoff and landing. 

  • Something which is limp or sagging. 

swab

verb
  • To use a swab on something, or clean something with a swab. 

noun
  • A sailor; a swabby. 

  • A naval officer's epaulet. 

  • A small piece of soft, absorbent material, such as gauze, used to clean wounds, apply medicine, or take samples of body fluids. Often attached to a stick or wire to aid access. 

  • A mop, especially on a ship. 

  • A piece of material used for cleaning or sampling other items like musical instruments or guns. 

  • A sample taken with a swab (piece of absorbent material). 

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