n. 1 each of the upper limbs of the human body from the shoulder to the hand. 2 a the forelimb of an animal. b the flexible limb of an invertebrate animal (e.g. an octopus). 3 a the sleeve of a garment. b the side part of a chair etc., used to support a sitter's arm. c a thing resembling an arm in branching from a main stem (an arm of the sea). d a large branch of a tree. 4 a control; a means of reaching (arm of the law). an arm and a leg a large sum of money. arm in arm (of two or more persons) with arms linked. arm-wrestling a trial of strength in which each party tries to force the other's arm down on to a table on which their elbows rest. as long as your (or my) arm colloq. very long. at arm's length 1 as far as an arm can reach. 2 far enough to avoid undue familiarity. in arms (of a baby) too young to walk. in a person's arms embraced. on one's arm supported by one's arm. under one's arm between the arm and the body. within arm's reach reachable without moving one's position. with open arms cordially. armful n. (pl. -fuls). armless adj.
[ OE f. Gmc ]