prophylactic vs sheath

prophylactic

noun
  • A prophylactic condom. 

  • A medicine which preserves or defends against disease; a preventive. 

  • Any device or mechanism intended to prevent harmful consequences. 

adj
  • Serving to prevent or protect against an undesired effect, especially disease or pregnancy 

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 prophylactic and sheath occurred in a corpus of books? (source: Google Ngram Viewer )