incongruous vs of a piece

incongruous

adj
  • Of two numbers, with respect to a third, such that their difference can not be divided by it without a remainder. 

  • Not similar or congruent; not matching or fitting in. 

of a piece

prep
  • Used other than figuratively or idiomatically: see of, a, piece. 

  • Of the same kind. 

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