muzzle

A muzzle is usually something that covers an animal's mouth to prevent it from biting or making noise.

You might have seen pictures of dogs wearing muzzles when they go on walks. That's because some dogs get overexcited and start barking loudly, so a muzzle helps keep them quiet. But a muzzle can also refer to the front of a gun, where you put your fingers to hold it steady while shooting. In this case, a muzzle is more like a narrow end or a pointy tip, rather than something that covers an animal's face.