arm1
¦ noun
1. each of the two upper limbs of the human body from the shoulder to the hand.
a limb of an octopus, starfish, or other animal.
2. a side part of a chair supporting a sitter's arm.
3. a narrow strip of water or land projecting from a larger body.
4. a branch or division of an organization.
5. Mathematics each of the lines enclosing an angle.
Phrases
arm in arm with arms linked.
cost an arm and a leg informal be extremely expensive.
would give one's right arm for informal wish for desperately.
in arms (of a baby) too young to walk.
keep at arm's length avoid intimacy or close contact with.
the long (or strong) arm of the law the far-reaching power of the law.
with open arms with great affection or enthusiasm.
Derivatives
armful noun (plural armfuls).
armless adjective
armload noun
Origin
OE arm, earm, of Gmc origin.
--------
arm2
¦ verb
1. supply with weapons.
provide with essential equipment or information for a task or situation.
2. activate the fuse of (a bomb) so that it is ready to explode.
Origin
ME: from OFr. armer, from L. armare, from arma 'armour, arms'.