A Fresnel zone plate.

(baseball) A flat, pentagonal, rubber object placed at the center of the batter's box, which is used as a basis for judging pitched strikes and balls, and the touching of which by a runner advancing from or past third base scores a run.

Metallic armour made of large pieces or plates.

To plate something with chromium.

(UK, Australia) A plastic square sticker consisting of a large red letter P on a white background, placed on a vehicle to indicate that the driver only has a provisional (UK: probationary) driver's licence.

(transitive) To coat (something, especially steel sheet) with tin, either by dipping or electroplating.

A thin sheet of steel coated with tin to prevent rusting; used to make cans etc.

A slotted plate for carrying the gears of a lathe. / A Petri dish, divided into four, and containing agar and other materials, used in the identification of bacteria.

An identifying tag, usually of metal, bearing a unique sequence of letters, numbers, or both, and placed at the back and, sometimes, also at the front of a motor vehicle.

A thin layer of silver applied to the surface of an object made of another metal.