Quorum

 

A quorum is the number of members who must be present and accounted for in order to conduct business.

 

U.S. Senate Definition

 

"The number of senators that must be present for the Senate to do business. The Constitution requires a majority of senators (51) for a quorum. Often, fewer senators are actually present on the floor, but the Senate presumes that a quorum is present unless the contrary is shown by a roll call vote or quorum call.”