prophylaxis vs sheath

prophylaxis

noun
  • Prevention of, or protective treatment for, disease. 

  • A move or strategy that frustrates an opponent's plan or tactic. 

sheath

noun
  • A condom. 

  • The base of a leaf when sheathing or investing a branch or stem, as in grasses. 

  • A holster for a sword; a scabbard. 

  • The foreskin of certain animals (for example, dogs and horses). 

  • A tight-fitting dress. 

  • Anything that has a similar shape to a scabbard that is used to hold an object that is longer than it is wide. 

  • The insulating outer cover of an electrical cable. 

  • One of the elytra of an insect. 

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