butterfly valve vs wrest

butterfly valve

noun
  • A valve with a disk-shaped mechanism which can be used for isolating or regulating flow. 

wrest

noun
  • A partition in a water wheel by which the form of the buckets is determined. 

  • A key to tune a stringed instrument. 

  • The act of wresting; a wrench or twist; distortion. 

verb
  • To tune with a wrest, or key. 

  • To seize. 

  • To distort, to pervert, to twist. 

  • To obtain by pulling or violent force. 

  • To pull or twist violently. 

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