armor

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A defensive covering, as of metal, wood, or leather, worn to protect the body against weapons.
2. n. A tough, protective covering, such as the bony scales covering certain animals or the metallic plates on tanks or warships.
3. n. A safeguard or protection: faith, the missionary's armor.
4. n. The combat arm that deploys armored vehicles, such as tanks.
5. n. The armored vehicles of an army.
6. v. To cover with armor.

Century Dictionary and Cyclopedia

1. n. Defensive arms; any covering worn to protect the person against offensive weapons. All available materials that offer some resistance to edge or point have, at various epochs and among various peoples, been put to use for this purpose, as thick skins, garments of linen or of silk, stuffed with vegetable fiber, or made of many thicknesses of material, thin plates of horn or metal, sewed to some textile fabric and lapping over one another like scales, etc. Usually the headpiece was the first piece of armor to be made in solid metal. (See helmet.) The Greeks had a solid cuirass from a very early period. (See cuirass and thorax.) This, with the helmet and the greaves (see greave), constituted the whole armor of the heavy-armed Greek warrior of historic times. The Roman legionary was in general similarly armed, sometimes wearing only one greave. Chain-mail was introduced in the armor of the Roman soldiery. The Norman invaders of England in 1066 wore a conical helmet with a nasal or strong projecting piece of iron coming down over the nose, and long gowns of stuff to which were sewed rings or plates of metal, and the leaders had leg-coverings of similar make. A century later chain-mail was in common use. The knights of the time of Richard I. of England (Cœur de Lion, 1189–1199) wore a long hauberk of chain-mail, reaching to the knee or below, with long sleeves closed at the ends so as to form gloves, and with openings in the sides through which the hands could be passed, leaving the gloves hanging down from the wrist; hose of the same make, either covering the feet or worn with shoes of strong leather; or sometimes long hose of leather laced or buckled like modern long gaiters. A hood, called the camail, sometimes of chain-mail, sometimes of leather, covered the head and descended to the shoulders, and upon this rested the iron helmet, either of conical form or rounded or acorn-shaped, without vizor, pressing on the head at its lower edge, where it was often secured to the camail, and rising above the crown of the head. Very rarely in this reign a closed helmet was used, as seen on a seal of King Richard I.; helmets of this form became common early in the reign of Henry III. (1216–1272). By the time of Henry IV. (1399–1413) and his invasion of France (1411), the knight was completely clothed in armor of plates, chain-mail being used at the junction of the limbs with the body, at the elbow- and knee-joints, and for a hood covering the top of the corselet. Finally, under Henry VI. (1422–1461), at about the time that the English were driven out of France (1453), the suit of armor reached its complete development, being forged of thin steel to fit the body and limbs, weighing not over 60 or 70 pounds in all, and allowing of free movement. This, however, was extremely costly. The armor worn in jousts and tournaments was very different after the twelfth century from that worn in war, being heavier, and neither allowing the knight to dismount without assistance nor affording him adequate protection if dismounted. For war, in spite of the general adoption of firearms, armor, though not investing the whole body, continued to be worn by officers and mounted men until the close of the seventeenth century, in the wars of Louis XIV.'s reign, and, indeed, survives to this day in the helmets and cuirasses of certain corps of cavalry. (The cuts are from Viollet-le-Duc's “Dict. du Mobilier français.”)
2. n. The metallic sheathing, intended as a protection against projectiles, for a ship of war or the exposed face of a fortification. Figuratively, a defensive covering of any kind; that which serves as a protection or safeguard; a bulwark: used in zoology and botany of the protective envelop or cover of an animal or a plant, as the scales of a fish or the plates of a crocodile.
3. n. In magnetism, same as armature
4. To cover with armor or armor-plate.
5. n. In paleobotany, the thick covering or jacket which surrounds the woody axis of fossil cycadean trunks, consisting of the persistent leaf-bases and the copious ramentum which fills the interstices between them. The ramentum is firmly silicified, forming walls around the leaf-bases; and where, as is usually the case, only the lower portion of the leaf-bases is preserved, the triangular cavities remaining give to the trunks a honeycomblike appearance.

Wiktionary

1. n. uncountable A protective layer over a body, vehicle, or other object intended to deflect or diffuse damaging forces.
2. n. uncountable A natural form of this kind of protection on an animal's body.
3. n. uncountable Metal plate, protecting a ship, military vehicle, or aircraft.
4. n. countable A tank, or other heavy mobile assault vehicle.
5. n. military, uncountable A military formation consisting primarily of tanks or other armoured fighting vehicles, collectively.
6. n. 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.
7. v. transitive To equip something with armor or a protective coating or hardening.
8. v. transitive To provide something with an analogous form of protection.

GNU Webster's 1913

1. n. Defensive arms for the body; any clothing or covering worn to protect one's person in battle.
2. n. Steel or iron covering, whether of ships or forts, protecting them from the fire of artillery.

WordNet 3.0

1. v. equip with armor
2. n. a military unit consisting of armored fighting vehicles
3. n. protective covering made of metal and used in combat
4. n. tough more-or-less rigid protective covering of an animal or plant