General English

  • noun the part of the body which goes from the shoulder to the hand
  • noun the part of a chair which you can rest your arms on
  • verb to give weapons to


  • noun a device similar in function to a human arm, operating as a lever
  • noun the horizontal distance from a reference point to the centre of gravity
  • verb to make ready for action or use


  • verb to prepare a device or machine or routine for action or inputs
  • verb to define which interrupt lines are active


  • A mechanical device or element that serves to position objects. For example, an access arm in a computer disk drive.
  • A mechanical device or element which has multiple positions.
  • A path within a circuit or network. Also called leg, or branch (2).
  • In robotics, a set of links and powered joints which comprises all the parts of the manipulator, except for the wrist and the end-effector. Also called robot arm.

Health Economics

  • (written as Arm)
    In a controlled trial an arm is a group of patients allocated to a particular treatment. In a randomized controlled trial, the allocation to different arms is determined by a randomization procedure. Many controlled trials have two arms, one group of patients being assigned to the treatment arm and the other to the control arm. Trials may have more than two arms and more than one treatment or control arm.


  • noun the part of the body from the shoulder to the hand, formed of the upper arm, the elbow and the forearm


  • noun a branch of the armed forces (e.g., armour, artillery, infantry)
  • verb to prepare a shell, bomb, etc., by removing any safety mechanism
  • acronym foranti-radar missile
    (written as ARM)
  • noun a missile designed to home in on an enemy radar transmission.


  • noun a horizontal stroke on a character which is unconnected to another stroke at one end, such as the middle bar in ‘f’


  • noun power, influence, coercion. A colloquial coinage on the lines of ‘hold’, ‘grip’ or ‘strong-arm’.
  • noun a measurement of dagga. Recorded as an item of Sowetan slang in the Cape Sunday Times, 29 January 1995.


  • noun something shaped like an arm, or a piece at the side of a chair to rest your arms on


  • one of the woody parts of a vine that grow out of the cordon. Vines can be trained with the arms in different positions.

Origin & History of “arm”

The two distinct senses of arm, ‘limb’ and ‘weapon’, both go back ultimately to the same source, the Indo-European base *ar- ‘fit, join’ (which also produced art and article). One derivative of this was Latin arma ‘weapons, tools’, which entered English via Old French armes in the 13th century (the singular form was virtually unknown before the 19th century, but the verb arm, from Latin armāre via Old French armer, came into the language in the 13th century). The other strand is represented in several European languages, meaning variously ‘joint’, ‘shoulder’, and ‘arm’: Latin armus ‘shoulder’, e.g., and Greek harmos ‘joint’. The prehistoric Germanic form was *armaz, from which developed, among others, German, Dutch, Swedish, and English arm.