not effective

ADJECTIVE

ineffective

Synonyms

STRONGEST

feeble fruitless futile impotent inadequate incompetent indecisive ineffectual inefficient inept limited null powerless unable unproductive unprofitable unsuccessful worthless

WEAK

abortive anticlimactic barren bootless defeasible emasculate epicene feckless forceless idle inefficacious inferior innocuous inoperative lame neutralized no-go nugatory paltry slack-spined spineless unavailable unavailing unfruitful vain void withered

Antonyms

STRONGEST

able adequate capable competent dexterous effective effectual efficient expert fit fruitful potent powerful productive profitable skillful strong successful sufficient useful valuable worthwhile worthy

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.

There are no specific treatments for lobular breast cancer but they added that did not mean they were not effective and did not work.

From BBC • Jun. 17, 2026

That’s not effective fraud protection — that’s a broken system that is wasting money and creating friction with customers and vendors.

From MarketWatch • Apr. 22, 2026

"Punitive proposals like these are not effective against organized or transnational crime," said criminologist Erika Solis of the Catholic University of Peru.

From Barron's • Mar. 26, 2026

Current treatments for gout are not effective for everyone, and some individuals experience adverse reactions to existing uricase-based medications.

From Science Daily • Nov. 14, 2025

“Or it’s not effective on egglets,” Jordie puts in.

From "Linked" by Gordon Korman

not effective

Example Sentences

Related Words