A muzzle gag is a type of gag that is typically worn by a submissive partner during BDSM play. It is so named because of its strong resemblance to an animal muzzle, which is slid over an animal's snout to keep its mouth closed. Muzzle gags generally have a flexible patch of leather that is placed over the mouth. They are held in place by interconnected straps that wrap around the back of the head as well as straps that run under the chin and up over the face.
A muzzle gag may also be called a bondage muzzle.