(every) once in a while vs piecemeal

(every) once in a while

piecemeal

adj
  • Made or done in pieces or one stage at a time. 

verb
  • To divide or distribute piecemeal; dismember. 

noun
  • A fragment; a scrap. 

adv
  • Piece by piece; in small amounts, stages, or degrees. 

  • Into pieces or parts. 

How often have the words (every) once in a while and piecemeal occurred in a corpus of books? (source: Google Ngram Viewer )