Definition of "armor"

(uncountable) A protective layer over a body, vehicle, or other object intended to deflect or diffuse damaging forces.  examples

(uncountable) A natural form of this kind of protection on an animal's body.  examples

(uncountable) Metal plate, protecting a ship, military vehicle, or aircraft.  examples

(countable) A tank, or other heavy mobile assault vehicle.  examples

(military, uncountable) A military formation consisting primarily of tanks or other armoured fighting vehicles, collectively.  quotations

(hydrology, uncountable) The naturally occurring surface of pebbles, rocks or boulders that line the bed of a waterway or beach and provide protection against erosion.

(transitive) To equip something with armor or a protective coating or hardening.  examples

(transitive) To provide something with an analogous form of protection.  examples