pass out vs sink down

pass out

verb
  • To distribute, to hand out. 

  • To graduate, usually marked by a ceremony at the end of training. 

  • To end (a round) by having passes as the first four bids. 

  • Used other than figuratively or idiomatically: see pass, out. 

  • To graduate from university. 

  • To faint; to become unconscious. 

  • To become proficient in a particular job or task. 

sink down

How often have the words pass out and sink down occurred in a corpus of books? (source: Google Ngram Viewer )