muzzle vs nostril

muzzle

noun
  • The protruding part of an animal's head which includes the nose, mouth and jaws. 

  • The mouth or the end for entrance or discharge of a gun, pistol etc., that the bullet emerges from. 

  • A piece of the forward end of the plow-beam by which the traces are attached. 

  • A device used to prevent an animal from biting or eating, which is worn on its snout. 

  • A person's mouth. 

verb
  • To bind or confine an animal's mouth by putting a muzzle, as to prevent it from eating or biting. 

  • To bring the muzzle or mouth near. 

  • To restrain (from speaking, expressing opinion or acting); to gag; to silence; to censor. 

nostril

noun
  • Either of the two orifices located on the nose (or on the beak of a bird); used as a passage for air and other gases to travel the nasal passages. 

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