[ ih-fek-tiv ]
/ ɪˈfɛk tɪv /


adequate to accomplish a purpose; producing the intended or expected result: effective teaching methods; effective steps toward peace.
actually in operation or in force; functioning: The law becomes effective at midnight.
producing a deep or vivid impression; striking: an effective photograph.
prepared and available for service, especially military service.


a member of the armed forces fit for duty or active service.
the effective total of a military force.

Nearby words

  1. eff.,
  2. effable,
  3. efface,
  4. effect,
  5. effecter,
  6. effective conjugate,
  7. effective current,
  8. effective dose,
  9. effective half-life,
  10. effective osmotic pressure

Origin of effective

1350–1400; Middle English < Latin effectīvus practical, equivalent to effect(us), past participle of efficere (see effect) + -īvus -ive

SYNONYMS FOR effective
1. capable, competent. Effective, effectual, efficacious, efficient refer to that which is able to produce a (desired) effect. Effective is applied to that which has the power to, or which actually does, produce an effect: an effective action, remedy, speech. Effectual is used especially of that which produces the effect desired or intended, or a decisive result: An effectual bombardment silenced the enemy. Efficacious suggests the capability of achieving a certain end: an efficacious plan, medicine. Efficient (applied also to persons) implies the skillful use of energy or industry to accomplish desired results with little waste of effort: efficient methods; an efficient manager. 2. operative. 3. telling.

ANTONYMS FOR effective

Related forms
Can be confusedaffective effective (see synonym study at the current entry)

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for effectivities


/ (ɪˈfɛktɪv) /



a serviceman who is equipped and prepared for action
Derived Formseffectively, adverbeffectiveness, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for effectivities



late 14c., from French effectif, from Latin effectivus "productive, effective," from effect-, stem of efficere (see effect (n.)). Effectively in the sense of "actually" is attested by 1650s. Related: Effectivity.

Online Etymology Dictionary, © 2010 Douglas Harper