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

Knoepfler also notes that the same substance that's helpful at one dose might be ineffective or even harmful at another dose. —Sarah Boden, NPR, 23 Feb. 2026

Using on frozen or too-wet soil will be ineffective, and applying too late allows weeds to germinate. —Nishaa Sharma, The Spruce, 22 Feb. 2026

Attorneys in the murder trial Zimmerman has argued in court that his client received ineffective assistance from his trial attorneys, Dratman and Fischer. —Rosalio Ahumada, Sacbee.com, 21 Feb. 2026

In fact, many of the most popular ingredients right now are largely ineffective and won’t help your skin at all. —Leslie Baumann, Miami Herald, 20 Feb. 2026

Word History

First Known Use

1649, in the meaning defined at sense 1

Rhymes for ineffective

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

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