chew over vs doot

chew over

verb

  • To think deeply about; to ponder or mull over. 

doot

verb

  • think 

  • to scan 

  • to tap a card 

  • doubt 

noun

  • doubt 

  • beep (electronically-produced tone) 

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