gift vs reinforcer

gift

noun
  • The act, right, or power of giving or bestowing. 

  • Something given to another voluntarily, without charge. 

  • A talent or natural ability. 

  • Something gained incidentally, without effort. 

verb
  • To give as a gift or donation. 

  • To give away, to concede easily. 

reinforcer

noun
  • Something that reinforces; something that strengthens a behavior. 

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