efficacious

[ ef-i-key-shuh s ]
/ ˌɛf ɪˈkeɪ ʃəs /

adjective

capable of having the desired result or effect; effective as a means, measure, remedy, etc.: The medicine is efficacious in stopping a cough.

Origin of efficacious

1520–30; < Latin efficāci- (stem of efficāx) effectual. See efficient, -acious

OTHER WORDS FROM efficacious

Example sentences from the Web for efficacious

British Dictionary definitions for efficacious

efficacious
/ (ˌɛfɪˈkeɪʃəs) /

adjective

capable of or successful in producing an intended result; effective as a means, remedy, etc

Derived forms of efficacious

efficaciously, adverb efficaciousness, noun

Word Origin for efficacious

C16: from Latin efficāx powerful, efficient, from efficere to achieve; see effect