arm

noun (1)

Save Word

\ ˈärm

plural arms

Definition of arm

(Entry 1 of 5)

1 : a human upper limb especially : the part between the shoulder and the wrist

2 : something like or corresponding to an arm: such as

a : the forelimb of a vertebrate

b : a limb of an invertebrate animal

c : a branch or lateral shoot of a plant

d : a slender part of a structure, machine, or an instrument projecting from a main part, axis, or fulcrum

e : the end of a ship's yard also : the part of an anchor from the crown to the fluke — see anchor illustration

f : any of the usually two parts of a chromosome lateral to the centromere

3 : an inlet of water (as from the sea)

4 : a narrow extension of a larger area, mass, or group

5 : power, might the long arm of the law

6 : a support (as on a chair) for the elbow and forearm

7 : sleeve

8 : the ability to throw or pitch a ball well also : a player having such ability

9 : a functional division of a group, organization, institution, or activity the logistical arm of the air force

10 medical : a group of subjects provided a particular treatment in a clinical trial Since this trial did not include a radiation-only treatment arm, it has been questioned whether radiation therapy alone might be as effective as sequential chemotherapy and radiation therapy in preserving the larynx.— Everett E. Vokes et al.

arm in arm

: with arms linked together

arm

verb

armed; arming; arms

Definition of arm (Entry 2 of 5)

transitive verb

1 : to furnish or equip with weapons

2 : to furnish with something that strengthens or protects arming citizens with the right to vote

3 : to equip or ready for action or operation arm a bomb

intransitive verb

: to prepare oneself for struggle or resistance arm for combat

arm

noun (2), often attributive

Definition of arm (Entry 3 of 5)

1a : a means (such as a weapon) of offense or defense especially : firearm

b : a combat branch (as of an army)

c : an organized branch of national defense (such as the navy)

2 arms plural

a : the hereditary heraldic devices of a family

b : heraldic devices adopted by a government

3 arms plural

a : active hostilities : warfare a call to arms

b : military service

up in arms

: aroused and ready to undertake a fight or conflict

Arm

abbreviation (1)

Definition of Arm (Entry 4 of 5)

Armenian

ARM

abbreviation (2)

Definition of ARM (Entry 5 of 5)

adjustable rate mortgage

Other Words from arm Synonyms More Example Sentences Learn More About arm

Keep scrolling for more

Synonyms for arm

Synonyms: Noun (1)

firearm,
gun,
heat
[slang],
piece,
small arm

Synonyms: Noun (2)

Examples of arm in a Sentence

Verb They armed the men for battle. The group of fighters was armed by a foreign government. The two countries have been arming themselves for years, but now they have agreed to disarm. We armed ourselves with the tools we would need to survive in the forest. They arm people with accurate information. arming women with the right to vote Once the bomb has been armed, we have five minutes to escape.

History and Etymology for arm

Noun (1)

Middle English, going back to Old English earm, arm, going back to Germanic *arma-, masculine, (whence also Old Frisian erm "arm," Old Saxon arm, Old High German aram, arm, Old Norse armr, Gothic arms), going back to Indo-European *h₂orH-mo-, whence also Old Church Slavic ramo "shoulder," Bosnian-Croatian-Serbian rȁme, stem rȁmen-, Czech ráměk; a parallel zero-grade *h₂r̥H-mó- gives Old Prussian irmo "arm," Lithuanian (eastern dialects) ìrmėdė "pain from gout, chill, fever" (irm- "arm" + -ėdė "eating"), Sanskrit īrmá- "arm," Avestan arəma-; Latin armus "forequarter (of an animal), shoulder" probably goes back to *h₂erH-mo-

Note: Usually claimed to be a derivative of the verb *h₂er- "fit, join" (see arm entry 3)—very plausible semantically—though the Sanskrit and Baltic forms require a second laryngeal (*h₂erH-) in the base (cf. Rix et al., Lexikon der indogermanischen Verben, 2. Auflage, Wiesbaden, 2001, where the verbal base is posited without a second laryngeal). Could the suffix be *-H-mo-? The Slavic noun fluctuates in inflection between -mo- and -men- (see André Vaillant, Grammaire comparée des langues slaves, II:1 [Lyon, 1958], pp. 214-15). According to P. Schrijver, The Reflexes of the Proto-Indo-European Laryngeals in Latin (Amsterdam, 1991), p. 194, Latin armus cannot be traced to *h₂r̥H-mo-, which would have yielded *ramus. Regarding Armenian armukn "elbow," see H. K. Martirosyan, Etymological Dictionary of the Armenian Inherited Lexicon, Leiden, 2010, s.v.

Verb

Middle English armen, borrowed from Anglo-French armer, going back to Latin armāre, derivative of arma "implements of war, weapons, equipment" — more at arm entry 3

Noun (2)

Middle English armes (plural), "weapons, the military profession, heraldic devices," borrowed from Anglo-French, plural of arme "weapon," going back to Latin arma (neuter plural) "implements of war, weapons, equipment," derivative, with a suffix *-mo-, from a presumed verbal base *ar-, going back to Indo-European *h₂er- "fit, join," whence Greek reduplicated aorist ḗraron "(I) fit together, equipped, fit closely" (from which present tense ararískō, ararískein), ármenos (middle participle) "fitting, suited to," and (with suffixed *-smo- giving initial aspiration?) harmós "joint," hárma, harmat- "chariot, team of horses"; Armenian arari "(I) made," aṙnem "I make"

Note: See also art entry 1, arthro-, article entry 1, artiodactyl.

Keep scrolling for more

Buying Guide

Our team at The Usage has selected the best kettlebell of 2021.

Learn More About arm

Dictionary Entries Near arm

Arlon

arm

Arm

Statistics for arm

Cite this Entry

“Arm.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/arm. Accessed 17 Oct. 2021.

Style: MLA

MLA

Chicago

APA

Merriam-Webster Check Mark Icon

Keep scrolling for more

More Definitions for arm

arm

verb

English Language Learners Definition of arm

: to provide (yourself, a group, a country, etc.) with weapons especially in order to fight a war or battle

: to provide (someone) with a way of fighting, competing, or succeeding

: to make (a bomb, weapon, etc.) ready for use

arm

noun

\ ˈärm

Kids Definition of arm

(Entry 1 of 3)

1 : a human upper limb especially between the shoulder and wrist

2 : something like an arm in shape or position an arm of the sea the arm of a chair

3 : sleeve sense 1

4 : power entry 1 sense 1 the long arm of the law

5 : a foreleg of a four-footed animal

arm

verb

armed; arming

Kids Definition of arm (Entry 2 of 3)

1 : to provide with weapons

2 : to provide with a way of fighting, competing, or succeeding She armed her lawyer with facts.

arm

noun

Kids Definition of arm (Entry 3 of 3)

1 : weapon, firearm

2 : a branch of an army or of the military forces

3 arms plural : the designs on a shield or flag of a family or government

4 arms plural : actual fighting : warfare a call to arms

arm

noun

\ ˈärm

Medical Definition of arm

1a : a human upper limb

b : the part of the human upper limb between the shoulder and the wrist also : brachium

2a : the forelimb of a vertebrate other than a human being

b : a limb of an invertebrate animal

c : any of the usually two parts of a chromosome lateral to the centromere

3 : a group of subjects provided a particular treatment in a clinical trial Since this trial did not include a radiation-only treatment arm, it has been questioned whether radiation therapy alone might be as effective as sequential chemotherapy and radiation therapy in preserving the larynx.— Everett E. Vokes et al., The New England Journal of Medicine, 21 Jan. 1993

Keep scrolling for more

ARM

abbreviation