pounce vs pterygium

pounce

noun
  • Cloth worked in eyelet holes. 

  • Charcoal dust, or some other coloured powder for making patterns through perforated designs, used by embroiderers, lacemakers, etc. 

  • A sudden leaping attack. 

  • A type of fine powder, as of sandarac, or cuttlefish bone, sprinkled over wet ink to dry the ink after writing or on rough paper to smooth the writing surface. 

  • A punch or stamp. 

verb
  • To eagerly seize an opportunity. 

  • To sprinkle or rub with pounce powder. 

  • To attack suddenly by leaping. 

  • To leap into the air intending to seize someone or something. 

  • To strike or seize with the talons; to pierce, as with the talons. 

  • To stamp holes in; to perforate. 

pterygium

noun
  • An abnormal mass of tissue in the corner of the eye that obstructs vision 

  • A generalized limb of a vertebrate 

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