keel over vs straighten

keel over

verb
  • To collapse in a faint; to black out, to swoon. 

  • To die. 

  • Of a vessel: to roll so far on its side that it cannot recover; to capsize or turn turtle. 

straighten

verb
  • To cause to become straight. 

  • To clarify a situation or concept to (an audience). 

  • To bribe or corrupt. 

  • To stand up, especially from a sitting position. 

  • To become straight. 

  • To put in order; to sort; to tidy up. 

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