hear it again

: the number of members of an organization required to be present in order for business to be carried on

Example sentence:
The council meeting had to be postponed when there weren't enough citizens present to make up a quorum.

Etymology:
"Quorum" comes from a Middle English term that referred to a group of justices of the peace. (A justice of the peace is a local government official who performs duties such as administering oaths and marrying people.) That term traces back to the Latin word "qui," which means "who." Long ago, "qui" was used in the government documents that gave a person the authority to serve as a justice of the peace. Today, "quorum" usually refers to the number of members of a body (such as a legislature or board) who are legally able to carry on business.