Armor or armour?

It’s not a loaded question. Armour and armor are simply two spellings of the same word. British English uses “armour,” while American English prefers “armor.”

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What is the difference between armor and armour?

Practicing writers often ask The Word Counter whether they should use the spelling armour or armor, and the answer is pretty simple: 

  • Use “armour” for British audiences
  • Use “armor” for American audiences

What does the word armor mean?

The noun armor (also spelled “armour” in Brit. Eng.) references anything that protects something in a defensive manner. In most cases, we use the noun to describe a defensive covering worn in combat (esp. the protective metal plates worn by medieval warriors). 

A more natural form of this kind of protection also includes:

  • The epidermis of plants (including thorns, bark, and wax coating)
  • The shell of certain animals (such as the carapace of a lobster)
  • Naturally occurring fortifications around the bed of a waterway to protect against erosion
  • Someone’s social, emotional, or economic status (such as wealth, knowledge, attitude, or certain trauma responses)


Capsule, case, casing, cocoon, cover, covering, defense, encasement, guard, housing, hull, husk, jacket, pod, protection, safeguard, security, sheath, shell, shield, wall.


Aggression, assault, attack, offense, offensive.

Etymology of armor/armour

According to Lexico, the word armor is a Middle English noun that derives from Old French armure via Latin armatura (from armare, meaning ‘to arm’). 

Additional information on battle armor/amour

Ever heard of a “knight in shining armor”? If so, that’s because one of the most common interpretations of “armor” involves protective body coverings adorned by medieval knights between the 9th and 15th centuries (although they were not as  “chivalrous” as we are led to believe).

According to Merriam-Webster’s Dictionary, a knight’s personal armor consisted of 14 parts to protect various parts of the body: 

  1. Helmet (head)
  2. Gorget (neck)
  3. Shoulder piece, “spaulder,” or “epaules” (shoulders)
  4. Pallette (armpit area)
  5. Breastplate or “cuirass” (torso)
  6. Brassard (upper arms)
  7. Elbow piece (elbows)
  8. Skirt of tasses (waist and hip area)
  9. Tuille (hips)
  10. Gauntlet (hands)
  11. Cuisse (thigh)
  12. Knee piece or “poleyn” (knees)
  13. Jambeau  or “greave” (lower leg)
  14. Solleret or “sabaton” (feet)

Knight armor evolved many times through the Middle Ages, so you can imagine how many variations of terms there are for specific parts of personal armor (including those for war animals). 

Additional body armor terms you might want to know include:

  • Chain mail: Metal chains woven into a protective layer of clothing (often as a “byrnie” or “hauberk,” which we might liken to a shirt). 
  • Ring mail: A larger version of chain mail attached to leather. 
  • Scale armor: overlapping or “scaled” iron plates (also attached to leather).
  • Splint armor: A minimalistic version of the knight’s suit of armor. 
  • Coat of armor: Also called a “coat of arms,” a coat of armor is a surcoat or tunic worn over armor with heraldic insignia embroidered to identify a soldier’s allegiance. 
  • Coat of plates: Torso armor consisting of segmented plates worn over a garment made of chain mail (also called “plate armour/armor”). 
  • Jack of plate: A medieval, felt vest with small iron plates sewn into the fabric.
  • Barding: A type of armor used for war horses in Europe. 

European knights were not the only type of “mounted armored warrior” who wore metal plates, either. Japanese samurai join a tall list of historical militaries who wore highly intricate armor with heavy iron plates to cover vital organs (many of which predate European knighthood). 

The use of armor/armour for modern military

Clearly, we don’t see many cavalry warriors on horseback these days, although police forces, security staff, and military personnel do wear helmets and ballistic vests. (In fact, law enforcement vests are fastened with metal plates that can withstand the caliber of their own weapon.) 

When it comes to modern-day military, you’re more likely to hear the word “armor” in reference to armored forces (large military units) and armored warfare (aka “tank warfare”)

As noted by Lexico, “armor” (or “armor plate”) can be a “tough metal layer covering a military vehicle or ship to defend it from battle” or “military vehicles collectively.” As a result, we often see the noun referencing mechanized infantry units, armored personnel carriers (APCs), infantry fighting vehicles (IFVs), or other types of armored warships and airplanes

The same distinction for APCs or IFVs does not apply to motorized infantry units (as discussed in calvary vs. cavalry), but that’s because their vehicles are only used to transport soldiers to combat. APCs and IFVs are specifically designed to transport and armor soldiers during combat while providing “armament” (a niche word for military artillery and equipment like machine guns, automatic cannons, or anti-tank guided missiles). 

Armor/armour as a verb

To armor” (or armour) something is to equip a person, animal, or object with a form of armor, protective layer, or hardening. In some cases, this means the verb conveys the act “ensheathing” or “encapsulating” something.


Cocoon, encapsulate, encapsule, encyst, ensheathe, ensphere, enwomb.

How to use armor or armour in a sentence?

Sometimes the easiest way to understand a term is to learn by example. Let’s take a look at how other writers have used armor as a noun and verb by subject. 

Biological or environmental armor/armour

  • “Scales cover the bodies — and even the eyeballs — of sharks. Known as “dermal denticles,” these scales function like protective armor and their ridges also reduce drag as the animals swim…” — The New York Times
  • “Solana Beach has a weak spot in its armor, and the California Coastal Commission is refusing to let homeowners fix it.” — Los Angeles Times
  • “But it was when we discovered its first radiant, chrome-yellow blooms of the season, packed between jagged grey rocks armouring the sea wall against the waves at the mouth of the river…” — The Guardian

Emotional or social armor/armour

  • “Self-knowledge is touted as a kind of armor — if you know what you like and what to ask for, you can’t be exploited.” — The New York Times
  • “‘I thought I was going to lose my mind’ during treatment, she said, so before her daily hospital trips, she’d armor herself in outré outfits.” — The Wall Street Journal
  • “This is a place where you can take your armor off. We want people to feel safe here and like they belong.” — Los Angeles Times

Battle armor/armour

  • “Beside the barricades and roadblocks, the female vigilantes have a homemade tank, a heavy-duty pickup truck with steel plate armor welded on it.” — AP News
  • “Gamers for years have spent big on gear—such as weapons, armor or tools to strengthen their characters—in games like Fortnite, Minecraft and World of Warcraft.” — The Wall Street Journal
  • “The Louvre museum in Paris has announced the recovery of a set of gold and silver-encrusted Renaissance-era armour – nearly 40 years after it was stolen.” — The Guardian

Additional reading for armor vs. armour

If you’re interested in learning more spelling differences between American and British English, be sure the read the following lessons from The Word Counter:

Test Yourself!

Test how well you understand armor and armour with the following multiple-choice questions. 

  1. True or false?: A British audience will prefer the spelling of “amor” over “armour.”
    a. True
    b. False
  2. True or false?: The word armor can encompass a heavy mobile assault vehicle fastened with artillery devices.
    a. True
    b. False
  3. The word armor does not reference _____________.
    a. Metallic sheathing
    b. The shell of some animals
    c. Direct contact weapons such as swords and lances
    d. Military formation with fighting vehicles
  4. “To armor” (verb) is to ___________.
    a. Create fortifications using rocks and boulders
    b. Provide with any analogous form of protection
    c. To fasten a protective coating over a war animal’s body
    d. All of the above
  5. A form of “personal armour” or “armor” can include _________. 
    a. Under armor garments made by Nike or Adidas
    b. Safety garments worn on construction sites
    c. Vehicle armour/armor
    d. A and B
  6. The type of armor associated with European knights and other foot soldiers were commonplace in the _____________. 
    a. 14th century
    b. 16th century
    c. 17th century
    d. All of the above


  1. B
  2. A
  3. C
  4. D
  5. D
  6. A


  1. Armament.” Lexico, Oxford University Press, 2021.
  2. Armour.” Lexico, Oxford University Press, 2021.
  3. Amor.” The Dictionary, Merriam-Webster Inc., 2021.
  4. Amor.”The Thesaruas, Merriam-Webster Inc., 2021.
  5. Armor in British English.” Collins English Dictionary, HarperCollins Publishers, 2021.
  6. Boone, L. “She built a garden sanctuary in L.A. Now, she wants to share it with you.” Los Angeles Times,, 31 Mar 2021.
  7. Breiding, Dirk H. “Horse Armor in Europe.” Department of Arms and Armor, The Metropolitan Museum of Art, Mar 2010.
  8. Coat of arms.” The Dictionary, Merriam-Webster Inc., 2021.
  9. Diehl, P. “A weak spot in Solana Beach’s seaside armor.” Los Angeles Times,, 10 May 2021. 
  10. Gates, P. “A floral masterpiece.” The Guardian,, 19 Mar 2015.
  11. Kornei, K. “Sharks Almost Went the Way of the Dinosaurs 19 Million Years Ago.” The New York Times,, 3 Jun 2021. 
  12. Levels of Body Armor.” Criminal Justice Testing and Evaluation Consortium,, n.d. 
  13. Norris, M. “Feudalism and Knights in Medieval Europe.” Department of Education, The Metropolitan Museum of Art, Oct 2001. 
  14. Paris Louvre recovers 16th-century armour stolen nearly 40 years ago.” The Guardian,, 3 Mar 2021.
  15. Sehgal, P. “Yes, No, Maybe So: A Generation of Thinkers Grapples With Notions of Consent.” The New York Times,, 21 Jun 2021. 
  16. Solis, A. “In Mexico, women take the front lines as vigilantes.” AP News,, 15 Jan 2021. 
  17. Quiroz-Gutierrez, M. “NFTs Are Spurring a Digital Land Grab—in Videogame Worlds.” The Wall Street Journal,, 22 Mar 2021.
  18. Zarrella, K. K. “Why ‘Joy Dressing’ Is Summer’s Biggest Fashion Trend.” The Wall Street Journal,, 28 May 2021.