SOS vs flap

SOS

noun
  • A children's game in which players take turns to place S's and O's on a grid, collecting points by creating an "SOS" sequence. 

  • The conventional Morse code call made by a ship in distress. 

flap

verb
  • To move loosely back and forth. 

  • To move (something broad and loose) up and down. 

  • Of a resource or network destination: to be advertised as being available and then unavailable (or available by different routes) in rapid succession. 

noun
  • A side fin of a ray. 

  • A consonant sound made by a single muscle contraction, such as the sound /ɾ/ in the standard American English pronunciation of body. 

  • The motion of anything broad and loose, or a sound or stroke made with it. 

  • Anything broad and flexible that hangs loose, or that is attached by one side or end and is easily moved. 

  • A piece of tissue incompletely detached from the body, as an intermediate stage of plastic surgery. 

  • A hinged leaf. 

  • The labia, the vulva. 

  • A hinged surface on the trailing edge of the wings of an aeroplane, used to increase lift and drag. 

  • A controversy, scandal, stir, or upset. 

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