Elbow/ˈelbəʊ/ Definition 1 of 4Pro Tip 1/3Human Anatomy Used to refer to the actual joint in the human body. After long hours at the computer, her elbow became stiff. Pro Tip 2/3Common Injury Often mentioned when talking about injuries related to falls or sports. She wrapped a bandage around her swollen elbow. Pro Tip 3/3Idiomatic Expressions Part of expressions like 'to cost an arm and a leg', metaphorically including the elbow. That designer dress costs an arm and a leg.