Dictionary.com
definitions

arm

1
[ahrm]
See more synonyms for arm on Thesaurus.com
noun
  1. the upper limb of the human body, especially the part extending from the shoulder to the wrist.
  2. the upper limb from the shoulder to the elbow.
  3. the forelimb of any vertebrate.
  4. some part of an organism like or likened to an arm.
  5. any armlike part or attachment, as the tone arm of a phonograph.
  6. a covering for the arm, especially a sleeve of a garment: the arm of a coat.
  7. an administrative or operational branch of an organization: A special arm of the government will investigate.
  8. Nautical. any of the curved or bent pieces of an anchor, terminating in the flukes.
  9. an armrest.
  10. an inlet or cove: an arm of the sea.
  11. a combat branch of the military service, as the infantry, cavalry, or field artillery.
  12. power; might; strength; authority: the long arm of the law.
  13. Typography. either of the extensions to the right of the vertical line of a K or upward from the vertical stem of a Y.
Idioms
  1. an arm and a leg, a great deal of money: Our night on the town cost us an arm and a leg.
  2. arm in arm, with arms linked together or intertwined: They walked along arm in arm.
  3. at arm's length, not on familiar or friendly terms; at a distance: He's the kind of person you pity but want to keep at arm's length.
  4. in the arms of Morpheus, asleep: After a strenuous day, he was soon in the arms of Morpheus.
  5. on the arm, Slang. free of charge; gratis: an investigation of policemen who ate lunch on the arm.
  6. put the arm on, Slang.
    1. to solicit or borrow money from: She put the arm on me for a generous contribution.
    2. to use force or violence on; use strong-arm tactics on: If they don't cooperate, put the arm on them.
  7. twist someone's arm, to use force or coercion on someone.
  8. with open arms, cordially; with warm hospitality: a country that receives immigrants with open arms.

Origin of arm

1
before 900; Middle English; Old English earm; cognate with Gothic arms, Old Norse armr, Old Frisian erm, Dutch, Old Saxon, Old High German arm (German Arm) arm; Latin armus, Serbo-Croatian rȁme, rȁmo shoulder; akin to Sanskrit īrmá, Avestan arəma-, OPruss irmo arm; not akin to Latin arma arm2
Related formsarmed, adjectivearm·like, adjective
Can be confusedalms arms

arm

2
[ahrm]
noun
  1. Usually arms. weapons, especially firearms.
  2. arms, Heraldry. the escutcheon, with its divisions, charges, and tinctures, and the other components forming an achievement that symbolizes and is reserved for a person, family, or corporate body; armorial bearings; coat of arms.
verb (used without object)
  1. to enter into a state of hostility or of readiness for war.
verb (used with object)
  1. to equip with weapons: to arm the troops.
  2. to activate (a fuze) so that it will explode the charge at the time desired.
  3. to cover protectively.
  4. to provide with whatever will add strength, force, or security; support; fortify: He was armed with statistics and facts.
  5. to equip or prepare for any specific purpose or effective use: to arm a security system; to arm oneself with persuasive arguments.
  6. to prepare for action; make fit; ready.
Idioms
  1. bear arms,
    1. to carry weapons.
    2. to serve as a member of the military or of contending forces: His religious convictions kept him from bearing arms, but he served as an ambulance driver with the Red Cross.
  2. take up arms, to prepare for war; go to war: to take up arms against the enemy.
  3. under arms, ready for battle; trained and equipped: The number of men under arms is no longer the decisive factor in warfare.
  4. up in arms, ready to take action; indignant; outraged: There is no need to get up in arms over such a trifle.

Origin of arm

2
1200–50 for v.; 1300–50 for noun; (v.) Middle English armen < Anglo-French, Old French armer < Latin armāre to arm, verbal derivative of arma (plural) tools, weapons (not akin to arm1); (noun) Middle English armes (plural) ≪ Latin arma, as above
Related formsarm·less, adjective

Synonyms for arm

See more synonyms for on Thesaurus.com
8. outfit.

Antonyms for arm

5. deactivate, disarm.

Arm

  1. Armenian.

ARM

  1. adjustable-rate mortgage.

Ar.M.

  1. Master of Architecture.

Origin of Ar.M.

From the New Latin word Architecturae Magister

Arm.

  1. Armenian.
  2. Armorican.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for arm

rod, wing, branch, division, force, power, affiliate, load, protect, prepare, supply, provide, strengthen, fortify, mobilize, handle, stump, projection, bough, bow

Examples from the Web for arm

Contemporary Examples of arm

Historical Examples of arm

  • His arm was about her waist, and hers rested on his shoulder.

    Philothea

    Lydia Maria Child

  • Suddenly Eucoline touched my arm with a quick and timid motion.

    Philothea

    Lydia Maria Child

  • She arose, gently placed his arm on the couch, and looked upon his face.

    Philothea

    Lydia Maria Child

  • Each instinctively touched the other's arm, as a signal for silence.

    Philothea

    Lydia Maria Child

  • For an hour he watched her, feeling the arm on which she lay growing numb.

    The Spenders

    Harry Leon Wilson

British Dictionary definitions for arm

arm

1
noun
  1. (in man) either of the upper limbs from the shoulder to the wristRelated adjective: brachial
  2. the part of either of the upper limbs from the elbow to the wrist; forearm
    1. the corresponding limb of any other vertebrate
    2. an armlike appendage of some invertebrates
  4. an object that covers or supports the human arm, esp the sleeve of a garment or the side of a chair, sofa, etc
  5. anything considered to resemble an arm in appearance, position, or function, esp something that branches out from a central support or larger massan arm of the sea; the arm of a record player
  6. an administrative subdivision of an organizationan arm of the government
  7. power; authoritythe arm of the law
  8. any of the specialist combatant sections of a military force, such as cavalry, infantry, etc
  9. nautical See yardarm
  10. sport, esp ball games ability to throw or pitchhe has a good arm
  11. an arm and a leg informal a large amount of money
  12. arm in arm with arms linked
  13. at arm's length at a distance; away from familiarity with or subjection to another
  14. give one's right arm informal to be prepared to make any sacrifice
  15. in the arms of Morpheus sleeping
  16. with open arms with great warmth and hospitalityto welcome someone with open arms
verb
  1. (tr) archaic to walk arm in arm with
Derived Formsarmless, adjectivearmlike, adjective

Word Origin for arm

Old English; related to German Arm, Old Norse armr arm, Latin armus shoulder, Greek harmos joint

arm

2
verb (tr)
  1. to equip with weapons as a preparation for war
  2. to provide (a person or thing) with something that strengthens, protects, or increases efficiencyhe armed himself against the cold
    1. to activate (a fuse) so that it will explode at the required time
    2. to prepare (an explosive device) for use by introducing a fuse or detonator
  4. nautical to pack arming into (a sounding lead)
noun
  1. (usually plural) a weapon, esp a firearm
See also arms

Word Origin for arm

C14: (n) back formation from arms, from Old French armes, from Latin arma; (vb) from Old French armer to equip with arms, from Latin armāre, from arma arms, equipment

ARM

abbreviation for
  1. adjustable rate mortgage

Arm.

abbreviation for
  1. Armenia(n)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for arm
n.1

"upper limb," Old English earm "arm," from Proto-Germanic *armaz (cf. Old Saxon, Danish, Swedish, Middle Dutch, German arm, Old Norse armr, Old Frisian erm), from PIE root *ar- "fit, join" (cf. Sanskrit irmah "arm," Armenian armukn "elbow," Old Prussian irmo "arm," Greek arthron "a joint," Latin armus "shoulder"). Arm of the sea was in Old English. Arm-twister "powerful persuader" is from 1938. Arm-wrestling is from 1899.

They wenten arme in arme yfere Into the gardyn [Chaucer]
n.2

"weapon," c.1300, armes (plural) "weapons of a warrior," from Old French armes (plural), "arms, war, warfare," mid-13c., from Latin arma "weapons" (including armor), literally "tools, implements (of war)," from PIE root *ar- "fit, join" (see arm (n.1)). The notion seems to be "that which is fitted together." Meaning "heraldic insignia" (in coat of arms, etc.) is early 14c.; originally they were borne on shields of fully armed knights or barons.

v.

"to furnish with weapons," c.1200, from Old French armer or directly from Latin armare, from arma (see arm (n.2)). Related: Armed; arming.

Online Etymology Dictionary, © 2010 Douglas Harper
arm in Medicine

arm

[ärm]
n.
  1. An upper limb of the human body, connecting the hand and wrist to the shoulder.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Idioms and Phrases with arm

arm

In addition to the idioms beginning with arm

  • arm and a leg
  • armed to the teeth
  • arm in arm

also see:

  • at arm's length
  • babe in arms
  • forewarned is forearmed
  • give one's eyeteeth (right arm)
  • long arm of the law
  • one-armed bandit
  • put the arm on
  • shot in the arm
  • take up arms
  • talk someone's arm off
  • twist someone's arm
  • up in arms
  • with one arm tied behind
  • with open arms
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.