Your elbow is the bendy part of your arm between your wrist and your shoulder. Sometimes people use their pointy elbows to elbow people out of the way.
Your elbows are major joints in your arms, making it possible for you to do many things — including get scolded for having your elbows rudely on the table while you eat. Clothing can be said to have elbows as well: "I like your professor jacket with the patches on the elbows." Other inanimate objects with elbows include rivers and pipes: a sharp bend in either of these is also called an elbow.