arm

arm¹ / ärm/ • n. 1. each of the two upper limbs of the human body from the shoulder to the hand. ∎  (in technical use) each of these upper limbs from the shoulder to the elbow. ∎  each of the forelimbs of an animal. ∎  a flexible limb of an invertebrate animal, e.g., an octopus. ∎  a sleeve of a garment. ∎  an ability to throw a ball skillfully: he has a good arm. ∎  an athlete with such an ability. ∎  used to refer to the holding of a person's arm in support or companionship: he arrived with a pretty girl on his arm. ∎  used to refer to something perceived as powerful or protective: the comforting arms of the church. 2. a thing resembling an arm in form or function, in particular: ∎  a side part of a chair or other seat on which a sitter's arm can rest. ∎  a narrow strip of water or land projecting from a larger body. ∎  a large branch of a tree. ∎ fig. a long, narrow shape or object: a long arm of sunshine. 3. a branch or division of a company or organization: the political arm of the separatist group. ∎  one of the types of troops of which an army is composed, such as infantry or artillery. 4. Math. each of the lines enclosing an angle. PHRASES: arm in arm (of two or more people) with arms linked. the long arm of the law used to refer to the criminal justice system as far-reaching. at arm's length away from the body, with the arm fully extended: I held the telephone at arm's length. cost an arm and a leg inf. be extremely expensive. give one's right arm inf. used to convey a strong desire to have or do something: I'd give my right arm to go with them. in arms (of a baby) too young to walk: a babe in arms. keep someone/something at arm's length avoid intimacy or close contact with someone or something. under one's arm between one's arm and one's body: Barbara tucked the papers under her arm. with open arms with great affection or enthusiasm. within arm's reach near enough to reach by extending one's arm.DERIVATIVES: arm·ful / -ˌfoŏl/ n. (pl. -fuls) arm·less adj. arm² • v. [tr.] supply or provide with weapons: both sides armed themselves with grenades and machine guns. ∎  supply or provide with equipment, tools, or other items in preparation or readiness for something: she armed them with brushes and mops. ∎  activate the fuse of (a bomb or other device) so that it is ready to explode. • n. see arms.