Serving to initiate; initiatory.n. An introductory act or step; the first procedure in any enterprise; leading movement: as, to take the initiative.n. The power of commencing, originating, or setting on foot; the power of taking or the ability or disposition to take the lead: as, the popular branch of a legislature usually has the initiative in making appropriations.n. Specifically, the right to propose legislation, supplementary to the referendum.