A member is someone who belongs to a group, organization, or team. When you join the chess club at school, you become a member of that club. Your family members are the people who belong to your family. A member of Congress is someone elected to serve in the United States legislature.

Being a member usually involves sharing responsibilities, following certain rules, and working together toward common goals. A member of a soccer team practices with the group, plays in games, and supports their teammates. Library members can borrow books because they've joined the library system.

The word can also refer to a part of a larger whole. In mathematics, the numbers 2, 4, and 6 are members of the set of even numbers. Your arm is a member of your body (though we more commonly say “limb” in this context).

When you're a member of something, you're part of it, participating, contributing your effort, and sharing in what the group achieves together.