quorum n[Middle English, a select number of English justices of the peace formerly required to be present at sessions to constitute a lawful bench, from Latin, of whom, genitive plural of qui who; from the wording of the commission once issued to justices of the peace in England]
: the number (as a majority) of members or officers that must be present to conduct business [lacked a at the meeting of shareholders]
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.