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Showing results for effective.
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.

This raises the possibility that treatments targeting immune responses, such as immune-modulating drugs, could be effective for some patients.

From Science Daily • Apr. 25, 2026

The breakthrough arrived in 1955 when Dr. Jonas Salk introduced a safe and effective injected vaccine, funded by grassroots donations to the March of Dimes, then officially known as the National Foundation for Infantile Paralysis.

From The Wall Street Journal • Apr. 24, 2026

"Where there are credible allegations of human trafficking, the UK state, even if no victims come forward, has a positive legal obligation to conduct a prompt, effective and independent investigation," she said.

From BBC • Apr. 24, 2026

Adjust for those factors and the effective price/earnings ratio is lower, roughly in the high teens.

From Barron's • Apr. 24, 2026

“The ritual is more effective the closer both parties feel to each other!”

From "Kwame Crashes the Underworld" by Craig Kofi Farmer

Vocabulary lists containing effective

"Diary of a Wimpy Kid" by Jeff Kinney

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Hatchet

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STAAR English I: The Language of the Test 1

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