monokini vs swimming trunks

monokini

noun
  • A one-piece swimsuit, which may cover both the chest and the crotch (as contrasted with a bikini, which consists of two pieces). 

  • The lower part of a bikini without the upper part (i.e., topless). 

swimming trunks

noun
  • A pair of shorts or briefs worn for swimming or bathing. 

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