effective

Having the power to produce a required effect or effects.

Adjective

  1. Having the power to produce a required effect or effects.
    • The pill is an effective method of birth control.
    • "Capital idea; we'll go together and complain: two will be more effective," suggested Mr. Belting. - 1923, Ernest Bramah, The Eyes of Max Carrados:
    • Fire ants circumvented the problem of an ineffective sting by having an unusual and highly effective venom that when daubed or sprayed on other ants penetrates their waxy protective integumental barrier and kills or...

    Synonyms: efficacious

  2. Producing a decided or decisive effect.
    • The president delivered an effective speech!
    • Whosoever is an effective, real cause of doing his neighbour wrong, is criminal. - 1651, Jer[emy] Taylor, The Rule and Exercises of Holy Living. […], 2nd edition, London: […] Francis Ashe […], →OCLC:

    Synonyms: telling

  3. Efficient, serviceable, or operative, available for useful work.
    • How long does it take to make a bunch of civilians an effective military force?
    • My effective income after taxes and child support is $500 a month.
    • The effective radiated power is determined by multiplying the transmitter power output with the antenna gain.

    Antonyms: nominal

  4. Actually in effect.
    • effective immediately
    • The curfew is effective at midnight.
  5. Having no negative coefficients.
  6. Such that no group element acts trivially.
  7. approximate; Not describing the fundamental dynamic changes in some system as they happen.

Origin

Etymology tree Proto-Indo-European *h₁éǵʰ Proto-Indo-European *-s Proto-Indo-European *h₁éǵʰs Proto-Italic *eks Latin ex Latin ef- Proto-Indo-European *dʰeh₁k- Proto-Indo-European *-yéti Proto-Indo-European *dʰh₁kyéti Proto-Italic *θakjō Proto-Italic *fakjō Latin faciō Latin efficiō Proto-Indo-European *-wós Proto-Indo-European *-iHwósder. Latin -īvus Latin effectivusbor. French effectifder. English effective From French effectif, from Latin effectīvus (“productive; effective”), from efficiō (“to make; to bring about”), equivalent to effect + -ive.

Forms

more effective most effective eff.

Related

effect effectivity effectual efficacious efficacity efficacy efficiency efficient pseudoeffective

Derived

bioeffective brake mean effective pressure coeffective cost-effective effectivate effective accelerationism effective accelerationist effective altruism effective altruist effective compression effective dose effective energy effectively effectiveness effective nuclear charge effective radiated power effective stack size effectivization effectivize Effie equieffective geoeffective ineffective isoeffective

Noun

  1. a soldier fit for duty
    • The Army of the West reached Corinth sometime after the battle of Shiloh. We were 15,000 effectives, and brought Beauregard's effective force up to 45,000 men. - 1876, Dabney Herndon Maury; Southern Historical Society...

Forms

effectives eff.