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 could deliver a quick, effective speech, or hold a proper press conference.

From The Daily Beast

If the embargo were effective, the Castro brothers would have been doing Love Letters with the Duvaliers years ago.

From The Daily Beast

Build evidence about the practices, policies, and programs that will achieve the most effective and efficient results.

From The Daily Beast

While there are a couple of antibiotics that usually work, if they are overused they, too, may cease to be effective.

From The Daily Beast

In order to know what innovations work, you have to have good information on how effective your practices are.

From The Daily Beast

Whatever can be done to bring about the prompt and effective use of this new system of bank settlement will be done.

From Project Gutenberg

It is a notable fact that under the wholly unusual circumstances prevailing, the recovery was so prompt and effective.

From Project Gutenberg

However able the matter, the reading, in my judgment, is much less effective than the spontaneous expression of the speaker.

From Project Gutenberg

Thus they had secured a monopoly in Munster and an effective competition with us in poor Connaught.

From Project Gutenberg

It was ten minutes before she raised her hand and pointed to a wilted but still effective screen.

From Project Gutenberg

Related Words

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