effectively

UK: /ɪˈfɛktɪvli/

WordReference Random House Learner's Dictionary of American English © 2026

ef•fec•tive /ɪˈfɛktɪv/   adj. 

1. able to accomplish a purpose:
   very effective teaching methods.
2. in operation or in force;
   functioning:
   The law becomes effective at midnight.
3. real;
   actual;
   in fact but not in theory:
   [before a noun] The militia was the effective government at the time.
4. producing a deep or strong impression;
   striking:
   an effective photograph.

ef•fec•tive•ly, adv. 
ef•fec•tive•ness, n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2026

ef•fec•tive  (i fek′tiv), adj. 

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

n. 

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

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

ef•fec′tive•ly, adv. 
ef•fec′tive•ness, ef•fec•tiv′i•ty, n. 
Synonyms

• 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 esp. 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

• 1. futile, useless.