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Definitions

effective

[ih-fek-tiv, ee-fek‐] / ɪˈfɛk tɪv, iˈfɛk‐ /
ADJECTIVE
successful, persuasive
Synonyms
STRONGEST
active adequate compelling competent direct efficient forceful impressive potent powerful practical successful useful valid
STRONG
effectual efficacious
WEAK
able big-wheel capable cogent convincing emphatic energetic forcible having lead in pencil live moving on the ball operative persuasive playing hardball powerhouse producing resultant serviceable serving sound striking telling trenchant virtuous wicked yielding
Antonyms
STRONGEST
helpless impotent inadequate incapable incompetent ineffective inefficient insufficient unable useless weak worthless
STRONG
unproductive unsuccessful
WEAK
fruitless inoperative
ADJECTIVE
in use at the time
Synonyms
STRONGEST
active direct dynamic
WEAK
actual current in effect in execution in force in operation operative real
Antonyms
STRONGEST
inactive
WEAK
fruitless impotent incapable ineffective inoperative unproductive useless weak

Usage

What are other ways to say effective? The adjective effective is applied to a person or a thing that has the power to, or which actually does, produce an effect: an effective boss, remedy, speech. Effectual is used especially of that which produces the effect desired or intended, or a decisive result: An effectual bombardment silenced the enemy. Efficacious suggests the capability of achieving a certain end: an efficacious plan, medicine. Efficient (applied also to persons) implies the skillful use of energy or industry to accomplish desired results with little waste of effort: efficient methods; an efficient manager. 

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

It’s more effective than trying to “boil the ocean with your entire data strategy,” according to Cramer.

From MarketWatch • Apr. 4, 2026

Petrol will see a 42.7 percent increase effective on Friday while diesel will be hiked 54.9 percent.

From Barron's • Apr. 3, 2026

Reverse-engineering existing technology yielded “the Toyota Corolla of drones”—cheap, easy to manufacture and devastatingly effective.

From The Wall Street Journal • Apr. 3, 2026

The company's process removes the contaminants and turns the nutrients into forms that can be taken up by plants, creating an "effective, safe - and odourless - fertiliser", she emphasised.

From BBC • Apr. 2, 2026

This method was particularly effective in the case of the dragon of Lambton Hall.

From "Jeremy Thatcher, Dragon Hatcher" by Bruce Coville

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.