feeler vs rain check

feeler

noun
  • Someone that assumes or imagines that one's affection is reciprocated; Someone that indulges in one's own wishful thinking; One who flatters oneself 

  • Someone or something that feels. 

  • Something ventured to test another's feelings, opinion, or position. 

  • An antenna or appendage used for feeling, especially on an insect. 

rain check

noun
  • In social interactions, a deferred invitation, or deferred acceptance of an invitation. 

  • to make good on any experience that the customer deems unsatisfactory. 

  • A reissue, at no extra charge, of a ticket for a baseball game or other outdoor event postponed or interrupted because of rain. 

  • to provide a sold-out item or temporarily unavailable service at a later date for the running (usually special) price. 

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