adjective ef·fec·tive \i-ˈfek-tiv, e-, ē-, ə-\

: producing a result that is wanted : having an intended effect

of a law, rule, etc. : in use

: starting at a particular time

Full Definition of EFFECTIVE

a :  producing a decided, decisive, or desired effect <an effective policy>
b :  impressive, striking <a gold lamé fabric studded with effective…precious stones — Stanley Marcus>
:  ready for service or action <effective manpower>
:  actual <the need to increase effective demand for goods>
:  being in effect :  operative <the tax becomes effective next year>
of a rate of interest :  equal to the rate of simple interest that yields the same amount when the interest is paid once at the end of the interest period as a quoted rate of interest does when calculated at compound interest over the same period — compare nominal 4
ef·fec·tive·ness noun
ef·fec·tiv·i·ty \ˌe-ˌfek-ˈti-və-tē, i-, ē-, ə-\ noun

Examples of EFFECTIVE

  1. It's a simple but effective technique.
  2. He gave an effective speech.
  3. These commercials were extremely effective as marketing tools, but we now know that chocolate swimming pools and candy-coating showers play no part in the manufacture of real M&M's. Instead, the ellipsoid chocolate centers of plain M&M's are formed by machines. —David Owen, Atlantic, October 1988


(see 1effect)
First Known Use: 14th century

Synonym Discussion of EFFECTIVE

effective, effectual, efficient, efficacious mean producing or capable of producing a result. effective stresses the actual production of or the power to produce an effect <an effective rebuttal>. effectual suggests the accomplishment of a desired result especially as viewed after the fact <the measures to stop the pilfering proved effectual>. efficient suggests an acting or a potential for action or use in such a way as to avoid loss or waste of energy in effecting, producing, or functioning <an efficient small car>. efficacious suggests possession of a special quality or virtue that gives effective power <a detergent that is efficacious in removing grease>.


noun ef·fec·tive \i-ˈfek-tiv, e-, ē-, ə-\

Definition of EFFECTIVE

:  one that is effective (see 1effective); especially :  a soldier equipped for duty


(see 1effect)
First Known Use: 1722
EFFECTIVENESS Defined for Kids


adjective ef·fec·tive \i-ˈfek-tiv\

Definition of EFFECTIVE for Kids

:  producing or able to produce a desired effect <effective medicines>
:  impressive <an effective speech>
:  being in operation <The rule is effective immediately.>
ef·fec·tive·ly adverb
ef·fec·tive·ness noun

Word Root of EFFECTIVE

The Latin word facere, meaning to make or to do, and its form factus give us the roots fic, fact, and fect. Words from the Latin facere have something to do with making or doing something. To manufacture is to make goods. This is often done in a factory. Something difficult is hard to do. Anything effective does what it is meant to do.
Medical Dictionary


adjective ef·fec·tive \i-ˈfek-tiv\

Medical Definition of EFFECTIVE

:  producing a decided, decisive, claimed, or desired effect <a drug judged effective by an evaluating panel>
ef·fec·tive·ly adverb
ef·fec·tive·ness noun


Next Word in the Dictionary: effective aperturePrevious Word in the Dictionary: effectibleAll Words Near: effective
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears