ruche vs transverse flute

ruche

noun
  • A strip of fabric which has been fluted or pleated. 

  • A small ruff of fluted or pleated fabric worn at neck or wrist. 

  • A pile of arched tiles, used to catch and retain oyster spawn. 

verb
  • To bunch up (fabric); to ruck up. 

  • To flute or pleat (fabric). 

transverse flute

noun
  • Any type of flute that is held sideways when played. 

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