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

But this month’s prolonged stretch of nighttime heat has made the practice ineffective. — Henry Grabar, The Atlantic, 27 June 2026

Staff said a fence installed to discourage people from gathering at the encampment has been ineffective. — Jason Rantala, CBS News, 24 June 2026

Skunks would rather put up with the strong scent of mothballs than leave a hospitable environment, making mothballs totally ineffective against skunks. — Michelle Mastro, The Spruce, 1 July 2026

Morocco was particularly ineffective, managing a single draw with Spain against two losses. — Anthony Crupi, Sportico.com, 30 June 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