[ ˌɛfɪ'keɪʃəs ]
■ adjective formal effective.
Derivatives
~ly adverb
~ness noun
efficacy 'ɛfɪkəsi noun
Origin
C16: from L. efficax , efficac- (from efficere 'accomplish') + -ious .
[ ˌɛfɪ'keɪʃəs ]
■ adjective formal effective.
Derivatives
~ly adverb
~ness noun
efficacy 'ɛfɪkəsi noun
Origin
C16: from L. efficax , efficac- (from efficere 'accomplish') + -ious .
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004