\Reg"nant\ (-nant), a. [L. regnans, -antis, p. pr. of
regnare to reign: cf. F r['e]gnant. See {Reign}.]
1. Exercising regal authority; reigning; as, a queen regnant.
2. Having the chief power; ruling; predominant; prevalent.
   ``A traitor to the vices regnant.'' --Swift.