membership

The state of belonging to a club or organization, often after paying a fee.

• My gym membership ends soon.
• She renewed her club membership yesterday.
• Does membership include free swimming lessons?

How to use it: membership of something (Membership of the club costs twenty pounds a year.); membership in something (Membership in the association is open to everyone.)

Common phrases: gym membership, annual membership, membership of something, membership in something

The fact that a number or other thing belongs to a particular mathematical group.

• This symbol expresses set membership.
• We tested each number for membership in the set.
• Membership depends on the rule defining the set.

How to use it: membership of a set (The symbol indicates membership of a set.)

Common phrases: set membership, membership relation, membership of something