effective

[ ih-fek-tiv, ee-fek‐ ]

adjective

1. adequate to accomplish a purpose; producing the intended or expected result:

   effective teaching methods; effective steps toward peace.

   Synonyms: competent, capable

   Antonyms: useless, futile

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. prepared and available for service, especially military service.

noun

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

effective

/ ɪˈfɛktɪv /

adjective

1. productive of or capable of producing a result
2. in effect; operative

   effective from midnight

3. producing a striking impression; impressive

   an effective entrance

4. prenominal actual rather than theoretical; real

   the effective income after deductions

5. (of a military force, etc) equipped and prepared for action
6. physics (of an alternating quantity) having a value that is the square root of the mean of the squares of the magnitude measured at each instant over a defined period of time, usually one cycle See also root mean square

noun

1. a serviceman who is equipped and prepared for action

Derived Forms

• efˈfectiveness, noun
• efˈfectively, adverb

Other Words From

• ef·fec·tive·ly adverb
• ef·fec·tive·ness ef·fec·tiv·i·ty [ih-fek-, tiv, -i-tee, ee-fek-] noun
• pre·ef·fec·tive adjective
• qua·si-ef·fec·tive adjective
• sub·ef·fec·tive adjective
• su·per·ef·fec·tive adjective
• un·ef·fec·tive adjective

Word History and Origins

Origin of effective¹

First recorded in 1350–1400; Middle English from Latin effectīvus “practical,” equivalent to effect(us), past participle of efficere ( effect ) + -īvus adjective suffix ( -ive )

Synonym Study

operative. telling.

Example Sentences

He was especially effective in neutralizing Galaxy winger Gabriel Pec, the team’s leading scorer.

From Los Angeles Times

But the evaluation also "highlights areas where further legal reforms are needed and makes reference to the need for effective enforcement, without which the risk of indecent working conditions could be elevated".

From BBC

It was regarded as one of the most effective and deadly of the groups ranged against President Assad.

From BBC

Two months after Cham’s arrest, the California Commission on Peace Officer Standards and Training temporarily suspended his peace officer certification effective Nov. 13, citing the pending criminal proceedings.

From Los Angeles Times

Based on your research into effective political activism, what can individuals who are concerned about climate change do to empower themselves in meaningful ways?

From Salon

Related Words

• active
• adequate
• compelling
• competent
• direct
• efficient
• forceful
• impressive
• potent
• powerful
• practical
• successful
• useful
• valid

When To Use

What are other ways to say effective?

The adjective effective describes things that are adequate to accomplish a purpose, or that produce the intended or expected result. But effective isn’t quite the same as effectual, efficacious, or efficient! Find out why on Thesaurus.com.