¹ arm noun

• either one of the two long body parts that join the top of your body at the shoulder and that end at the hand or wrist
• the part of a piece of clothing (such as a shirt or coat) that covers the arm : sleeve
• a part of a piece of furniture (such as a chair or couch) that gives support for a person's arm

² arm noun

• a gun or other weapon that is used especially in a war—usually plural —often used before another noun
• coat of arms

³ arm verb

• to provide (yourself, a group, a country, etc.) with weapons especially in order to fight a war or battle —often + with
• to provide (someone) with a way of fighting, competing, or succeeding
• to make (a bomb, weapon, etc.) ready for use