arm

AHRM/ɑɹm/UKAHM/ɑːm/

Pluralarms

Verbarms, arming, armed

21 meanings of arm

Practice

1
body limbnouncountable
One of the two long parts of your body between your shoulder and your hand.
She broke her arm falling off her bike.
He raised his arm to ask a question.
UsageSay my arm, his arm: I broke my arm.
Note
2
outfit to fightverbtransitive
To give people weapons, or to get weapons ready yourself, to be able to fight.
Like handing out tools before a job, except the tools are weapons.
Nations often arm their allies during a long war.
The general armed every recruit before the battle.
UsageSay arm someone with weapons. Armed police carry guns.
Similarequip
Oppositedisarm
Note
3
nouncountable
A tool made for fighting or hurting, like a gun or a sword.
Like a tool, but made for fighting instead of building.
The rifle was the main arm that every soldier carried into battle.
Soldiers laid down their arms after the truce.
UsageMostly arms: the arms trade, lay down their arms.
Similarweapon
Note
4
projecting partnouncountable
A long, thin part that sticks out from the main body of an object.
Like a branch reaching out from the trunk of a tree.
He rested his elbow on the arm of the chair.
The crane's long arm lifted the beam onto the roof.
Similarboom, jib
5
branchnouncountable
One part or branch of a larger group or company.
Like one branch of a tree that grows from the same trunk.
The charity's research arm studies new medicines.
This company has an arm in Asia.
UsageOften the bank's investment arm or the political arm of a group.
Similarbranch, division, wing, unit, section
6
verbfigurativelytransitive
To give someone the skills, facts, or tools they need to do something.
Like giving someone a toolbox before a job, but the tools are facts and skills.
Good teachers arm their students with useful skills.
The course armed her with the facts she needed.
UsageSay arm someone with facts or skills.
Similarequip, provide, furnish, supply, prepare
Note
7
family symbolsnounplural
Special pictures and patterns that stand for a family, city, or country.
Like a special badge that shows which family or town something belongs to.
The family's arms showed a golden lion on a red shield.
Above the gate, the city's arms were carved into the stone.
UsageMostly in coat of arms.
Similarinsignia, emblem, blazon
8
nounliteraryplural
War, fighting, or the brave acts done in battle.
UsageStill heard in take up arms, meaning start to fight.
Note

Less common meanings

9
activateverbtransitive
To set a weapon, alarm or system so that it is ready to go off or work.
Like switching on a machine so it is ready the moment you need it.
Press this button to arm the alarm before you leave.
She armed the security system at night.
UsageUsed for alarms and bombs. The opposite is disarm.
Oppositedisarm, deactivate
10
sleevenouncountable
The part of a shirt or coat that covers your arm.
He tore the arm of his jacket on a nail.
The arm of her sweater was too long.
UsageMost people say sleeve.
Similarsleeve
Note
11
pitchernounslangcountable
In baseball, a pitcher: the player who throws the ball to batters.
The coach was looking for a new arm to start the next few games.
They traded for a left-handed arm before the season began.
Similarpitcher, hurler
Note
12
sea animal limbnouncountable
A long body part that some animals without backbones use to move or grab things.
Like the long, bendy arms of an octopus that reach out to grab food.
An octopus can regrow an arm if it loses one.
The starfish wrapped its arms around the clam and pulled.
Similarlimb
13
powernounfigurativelycountable
Great power or strength, especially used to support or protect.
The small country relied on the strong arm of its bigger neighbor.
No one can escape the long arm of the law.
UsageUsed in phrases such as the long arm of the law and the strong arm of the state.
Similarpower, reach, hand
Note
14
inletnouncountable
A long, narrow part of a sea or lake that reaches into the land.
Like a finger of water reaching out from a big lake.
We sailed our boat up a quiet arm of the lake.
A narrow arm of the sea cut into the rocky coast.
Similarinlet, branch, channel
Note
15
trial groupnouncountable
One of the groups of people taking part in a medical study.
Like splitting players into two teams to see which one does better.
Each arm of the study tried a different medicine.
People in one arm got the new pill, and people in the other arm got nothing.
Similargroup, cohort
16
chromosomenouncountable
One of the two main sections of a chromosome.
Like the two parts of a stick joined at a knot in the middle.
Each chromosome has a short arm and a long arm.
The gene sits near the tip of the chromosome's long arm.
Note
17
reinforceverbtransitive
To cover something with a plate or other material to make it stronger or safer.
Like putting a hard case on a phone to keep it safe.
The hunters carried long poles armed with sharp iron points.
The old castle gate was armed with heavy iron plates.
Similarreinforce, armor, fortify, clad, plate
18
verbobsolete
To take someone by the arm, or to lift them up in your arms.
Arm your prize; / I know you will not lose him.
1613, John Fletcher, William Shak[e]speareHere, arm means to take someone by the arm, to hold on to him.
And make him with our pikes and partisans / A grave: come, arm him.
1611, William Shakespeare, “The Tragedie of Cymbeline”Here, arm means to lift a person up in your arms and carry him.
Note
19
verb
To fit a magnet with an armature, a piece of metal that keeps it strong.
20
adjectivedialectalScotlandUK
Poor, with little money.
21
adjectivedialectalScotlandUK
Very sad or unlucky, so that others feel pity.

Practice

Can you tell the meanings of arm apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origins

Meanings 1, 4–5, 10–16, 18

This word comes from Old English earm, meaning the body part. It goes back through Proto-Germanic to an ancient root meaning 'to join or fit together.'

Checked 31 Oct 2026 · 2 facts

Arm, referring to the body part, comes from Old English earm. en.wiktionary.org
The word descends through Proto-Germanic from a root meaning to join or fit together. en.wiktionary.org

Meanings 2–3, 6–9, 17

The noun comes from 'arms', from Latin arma, meaning weapons. The verb comes from French armer and Latin armare, 'to arm'.

Checked 31 Oct 2026 · 4 facts

The noun arm, meaning a weapon, comes from arms. en.wiktionary.org
Arms derives ultimately from Latin arma, meaning weapons. en.wiktionary.org
The verb derives from French armer and ultimately Latin armare. en.wiktionary.org
Latin armare means to arm. en.wiktionary.org