Meaning

noun a gathering of the minimal number of members of an organization to conduct business

originInherited from Middle English quorum (c. 1426), from Anglo-Norman quorum, clipped from the Anglo-Latin wording of commissions in which certain persons were specially designated as members of a body by the words quorum vos unum esse volumus ad etc. (“of whom we want you to be one assigned to etc.”). Latin quōrum is the masculine genitive plural of the relative pronoun quī (“who”).

Etymology from Wiktionary, CC BY-SA 3.0