Meanings
-
1
adj
Working well and producing the result you want.
The pill is an effective method of birth control.
-
2
adj
Officially in operation; starting to apply.
The new rules are effective immediately.
Thesaurus
Synonyms
2
adj
· officially in operation;...
in effectin force
Word family
Derived forms
bioeffectivecoeffectivecost-effectiveeffectivateeffectivelyeffectivenesseffectivizationeffectivizeeffieequieffectivegeoeffectiveineffective
Related forms
effecteffectivityeffectualefficaciousefficacityefficacyefficiencyefficientpseudoeffective
Etymology
From French effectif, from Latin effectīvus (“productive; effective”), from efficiō (“to make; to bring about”), equivalent to effect + -ive.
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