One who buckles something.

A kind of shield, of various shapes and sizes, held with a hand (usually the left) for protecting the front of the body. In the sword and buckler play of the Middle Ages in England, the buckler was a small shield, used, not to cover the body, but to stop or parry blows.

A shield resembling the Roman scutum. In modern usage, a smaller variety of shield is usually implied by this term.

To shield; to defend.