ineffective

adjective

in·​ef·​fec·​tive ˌi-nə-ˈfek-tiv 

1

: not producing an intended effect : ineffectual

ineffective lighting

an ineffective treatment

2

: not capable of performing efficiently or as expected : incapable

an ineffective executive

ineffectively adverb

ineffectiveness noun

Synonyms of ineffective

• unsuccessful
• inefficient
• counterproductive

Examples of ineffective in a Sentence

The treatment was ineffective against the disease.

an ineffective effort to reduce unemployment that only spurred inflation

Recent Examples on the Web

Pike’s unsuccessful appeals have alleged ineffective assistance of counsel and argued that executing her would be unconstitutional because of her mental illness, according to court documents. — Christina Coulter, PEOPLE, 25 Sep. 2026

After powerful antibiotics proved mostly ineffective, the experts from the aquarium and University of Florida developed a bacteriophage treatment for Jetta, according to a statement sent to Popular Science. — Margherita Bassi, Popular Science, 24 Sep. 2026

But enforcement actions often prove to be lacking and ineffective. — Michael L. Hyman, Miami Herald, 23 Sep. 2026

Board member Taylor Kayatta called the county office’s oversight ineffective. — Chaewon Chung, Sacbee.com, 22 Sep. 2026

Word History

First Known Use

1649, in the meaning defined at sense 1

Rhymes for ineffective

• imperfective
• intellective
• introspective
• irrespective
• nondirective
• nonselective
• retrospective
• unreflective
• advective
• affective
• collective
• connective

Kids Definition

ineffective

adjective

in·​ef·​fec·​tive ˌin-ə-ˈfek-tiv 

1

: not producing the desired effect

an ineffective law

2

: not performing as well as expected or needed

an ineffective leader

ineffectively adverb

ineffectiveness noun