a. [ L. eficax, -acis, fr. efficere. See Effect, n. ] Possessing the quality of being effective; productive of, or powerful to produce, the effect intended; as, an efficacious law.
Syn. -- See Effectual.
-- Ef`fi*ca"cious*ly, adv. [1913 Webster]
English-Thai: NECTEC'sLexitron-2 Dictionary [with local updates] NECTEC Lexitron Dictionary EN-TH
(adj) marked by qualities giving the power to produce an intended effect; -Aldous Huxley, Ant. inefficacious, Example:written propaganda is less efficacious than the habits and prejudices...of the readers; the medicine is efficacious in stopping a cough
(adv) in an effective manner, Syn. effectively, Ant. ineffectively, inefficaciously, Example:these are real problems that can be dealt with most effectively by rational discussion