Lewis & Short

factĭōsus, a, um, adj. [factio, II.], that has or seeks to form a party, powerful or eager for power, factious, seditious (class.; syn.: perduellis, seditiosus, tumultuosus, turbulentus, potens, praepotens): homo dives, factiosus, a demagogue, Plaut. Aul. 2, 2, 50: potens et factiosus, Auct. Her. 2, 26, 40: homo (with potens), Nep. Ages. 1: exsistunt in re publica plerumque largitores et factiosi, ut opes quam maximas consequantur, et sint vi potius superiores quam justitia pares, Cic. Off. 1, 19, 64: non divitiis cum divite, neque factione cum factioso, certabat, Sall. C. 54, 5; id. J. 31, 15 Dietsch: vel optimatium vel factiosa tyrannis illa vel regia, etc., i. e. oligarchical, Cic. Rep. 1, 29, 45: linguă factiosi, busy with the tongue, i. e. promising a great deal, Plaut. Bacch. 3, 6, 13.
Comp.: mulier, Aur. Vict. Caes. 21.
Sup.: quisque, Plin. Ep. 4, 9, 5.
* Adv.: factĭōse, mightily, powerfully, Sid. Ep. 4, 24.