noun, masculine/e.ta.ma.ʒɔʁ/plural: états-majors
general staff, high command, headquarters (group of officers in charge of an army under the control of the commander-in-chief); headquarters (military installation from which troops are commanded and orders are issued); administrative staff (body of staff that administers a political party); senior management (group of people in charge of a corporation); any administrative body aimed at aiding a professional or academic in their work
From état (“group, college”) + major (“main, principal”).