Arm/ɑːrm/ Definition 1 of 6Pro Tip 1/3Physical Injury Often used when discussing injuries or physical therapy. She's doing exercises to strengthen her arm after the injury. Pro Tip 2/3Literal Distance Used to describe the length or reach of something in physical terms. The bookshelf was an arm’s length away from me. Pro Tip 3/3Emotional Expression Describes intimacy or support when walking 'arm in arm' with someone. They walked arm in arm along the beach, enjoying the sunset.