Efficient most often describes what is capable of producing desired results without wasting materials, time, or energy. While the word can be applied to both people and things, it is far more commonly …

EFFECTIVE definition: 1. successful or achieving the results that you want: 2. (used about a treatment or drug) working…. Learn more.

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!

Definition of effective adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

Effective and efficient are often confused, but they have slightly different meanings. If you are effective, you do a job properly; if you are efficient, you do it quickly and easily.

When something such as a law or an agreement becomes effective, it begins officially to apply or be valid. The new rules will become effective in the next few days.

Jan 20, 2026 · Adjective effective (comparative more effective, superlative most effective) Having the power to produce a required effect or effects.

Effective, effectual, efficacious, efficient refer to that which is able to produce a (desired) effect. Effective is applied to that which has the power to, or which actually does, produce an effect: an effective …

The adjective effective has many shades of meaning, but you'll usually see it describing something that's able to produce a desired goal. Effective traces back to the Latin word effectivus, from efficere, …

From Longman Business Dictionary ef‧fec‧tive /ɪˈfektɪv/ adjective 1 working well and producing the result or effect that was wanted or intended The company mounted a very effective publicity campaign.