(1) The part of an armchair or sofa that supports the elbow and forearm of a seated person
(2) Any projection that is thought to resemble a human arm
"The arm of the record player"
"An arm of the sea"
"A branch of the sewer"
(3) The part of a garment that is attached at the armhole and that provides a cloth covering for the arm
(4) Any instrument or instrumentality used in fighting or hunting
"He was licensed to carry a weapon"
(5) A human limb; technically the part of the superior limb between the shoulder and the elbow but commonly used to refer to the whole superior limb
(6) An administrative division of some larger or more complex organization
"A branch of Congress"
(7) Prepare oneself for a military confrontation
"The U.S. is girding for a conflict in the Middle East"
"Troops are building up on the Iraqi border"
(8) Supply with arms
"The U.S. armed the freedom fighters in Afghanistan"