efficax

efficāx ācis, adj.with comp.and sup.

ex + 2 FAC-, efficacious, effectual, powerful, efficient : scientia (magica), H.: ad muliebre ingenium preces, L.: necessitas efficacior quam ratio, Cu.: in quibus (rebus) peragendis continuatio efficacissima, L.: amara Curarum eluere, H.