muzzle in WordNet English dictionary

1. restraint put into a person's mouth to prevent speaking or shouting
   gag  muzzle 
   
2. the open circular discharging end of a gun
   gun muzzle  muzzle 
   
3. forward projecting part of the head of certain animals; includes the jaws and nose
   muzzle 
   
4. a leather or wire restraint that fits over an animal's snout (especially a dog's nose and jaws) and prevents it from eating or biting
   muzzle 
   

1. tie a gag around someone's mouth in order to silence them
   "The burglars gagged the home owner and tied him to a chair"
   gag  muzzle 
   
2. prevent from speaking out
   "The press was gagged"
   gag  muzzle 
   
3. fit with a muzzle
   "muzzle the dog to prevent it from biting strangers"
   muzzle