A contrivance of metal, wood, or other material, made for the protection of an object from injury… In plural. The wards of a lock.

Something that serves to fend or keep off something else. A large piece of timber placed as a guard in front of any structure, esp. a pier…

Any of various technical devices which increase safety.

A screen or protection. Obsolete.

Something which affords or confers protection; a shield, a guard; a device or contrivance serving to prevent injury or damage to or from something…

figurative. Something designed to protect the security or integrity of a system, process, or institution, esp. by acting as a barrier; a measure…

= baffler, n. Also, any shielding device or structure, in many technical uses (see quots.); spec. an acoustic screen.