effective

American  

[ih-fek-tiv, ee-fek‐] / ɪˈfɛk tɪv, iˈfɛk‐ /

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.

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noun

1. a member of the armed forces fit for duty or active service.

2. the effective total of a military force.

effective British  

/ 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

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noun

1. a serviceman who is equipped and prepared for action

Usage

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.

Related Words

operative. telling.

Other Word Forms

• effectively adverb
• effectiveness noun
• effectivity noun
• preeffective adjective
• quasi-effective adjective
• subeffective adjective
• supereffective adjective
• uneffective adjective

Etymology

Origin of effective

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

Example Sentences

The analysis also suggests spending money on new medicines proved half as cost effective as improving existing services.

From The Wall Street Journal

The UK government on Monday said it will "invest around 25 percent more in innovative, safe, and effective treatments -- the first major increase in over two decades."

From Barron's

The legislation, effective Jan. 1, will add a potent mix of spending increases, tax cuts, and accounting changes.

From Barron's

"Of course, no solution is likely to be 100 percent effective all of the time," the internet safety watchdog has said.

From Barron's

Late October, Seoul struck a trade deal with Washington that lowered U.S. tariffs to 15% from 25% on most Korean goods, including vehicles, effective from Nov. 1.

From The Wall Street Journal

Related Words

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