effective

== English == === Alternative forms === eff. === Etymology === From French effectif, from Latin effectīvus (“productive; effective”), from efficiō (“to make; to bring about”), equivalent to effect +‎ -ive. === Pronunciation === (weak vowel distinction) IPA(key): /ɪˈfɛktɪv/ (weak vowel merger) IPA(key): /əˈfɛktɪv/ (Australian) IPA(key): /əˈfektɪv/ Homophone: affective (weak vowel merger) Rhymes: -ɛktɪv === Adjective === effective (comparative more effective, superlative most effective) Having the power to produce a required effect or effects. Synonym: efficacious Producing a decided or decisive effect. Synonym: telling Efficient, serviceable, or operative, available for useful work. Antonym: nominal Actually in effect. (geometry, of a cycle or divisor) Having no negative coefficients. (algebra, of a group action) Such that no group element acts trivially. (physics, for any effective theory) approximate; Not describing the fundamental dynamic changes in some system as they happen. ==== Usage notes ==== Webster's Revised Unabridged Dictionary from 1913 lists efficient and effective as synonyms, but all major dictionaries now show that these words now only have different meanings in careful use. Use of both for the other meaning is however widespread enough that Longman's Exam Dictionary, for example, finds it necessary to proscribe the use of one for the other with several examples at each entry and provides the following summary: efficient = working quickly and without waste effective = having the desired effect ==== Derived terms ==== ==== Related terms ==== ==== Translations ==== === Noun === effective (plural effectives) (military) a soldier fit for duty == French == === Pronunciation === IPA(key): /e.fɛk.tiv/ Homophone: effectives === Adjective === effective feminine singular of effectif == Latin == === Adjective === effectīve vocative masculine singular of effectīvus