n. - A kind of shield, of various shapes and sizes, worn on one of the arms (usually the left) for protecting the front of the body.
n. - One of the large, bony, external plates found on many ganoid fishes.
n. - The anterior segment of the shell of trilobites.
n. - A block of wood or plate of iron made to fit a hawse hole, or the circular opening in a half-port, to prevent water from entering when the vessel pitches.
v. t. - To shield; to defend.