effective
/ɪˈfɛktɪv/ adjective, noun
Forms effectives eff.
- adjective Having the power to produce a required effect or effects. “The pill is an effective method of birth control.”
- adjective Producing a decided or decisive effect. “The president delivered an effective speech!”
- adjective Efficient, serviceable, or operative, available for useful work. “How long does it take to make a bunch of civilians an effective military force?”
- adjective Actually in effect. “effective immediately”
- adjective (geometry, of a cycle or divisor) Having no negative coefficients.
- adjective (algebra, of a group action) Such that no group element acts trivially.
- adjective (physics, for any effective theory) approximate; Not describing the fundamental dynamic changes in some system as they happen.
- noun (military) a soldier fit for duty
Synonyms
efficacious telling effectual efficient good in effect in force
Antonyms
Etymology
From French effectif, from Latin effectīvus (“productive; effective”), from efficiō (“to make; to bring about”), equivalent to effect + -ive.
Webster’s 1913
- adjective Having the power to produce an effect or effects; producing a decided or decisive effect; efficient; serviceable; operative; as, an effective force, remedy, speech; the effective men in a regiment.
- noun That which produces a given effect; a cause. Jer. Taylor.
- noun One who is capable of active service.
Etymology [L. effectivus: cf. F. effectif.]
Etymology [F. effectif real, effective, real amount.]
Sources: Wiktionary · WordNet 3.0 · Webster’s 1913 — from the Wiktionary entry “effective”, CC BY-SA 4.0. Details