unsuccessful

adjective

un·​suc·​cess·​ful ˌən-sək-ˈses-fəl 

: not successful : not meeting with or producing success

unsuccessfully

ˌən-sək-ˈses-fə-lē 

adverb

Synonyms of unsuccessful

• futile
• useless
• abortive

Examples of unsuccessful in a Sentence

His last novel was unsuccessful.

an unsuccessful attempt to fix the faucet ourselves

Recent Examples on the Web

While some states voluntarily handed over the information, the department sued 30 states and the District of Columbia to obtain it -- lawsuits that so far have been unsuccessful. — Arkansas Online, 20 Oct. 2026

Marcel Felipe, a Cuban exile leader who helped advocate for the prosecution, described years of unsuccessful efforts to persuade local, state and federal officials to pursue charges. — Antonio María Delgado, Miami Herald, 19 Oct. 2026

The thought process was to get the five best offensive linemen on the field to spark the offense, but the change was largely unsuccessful. — Steven Johnson, Fort Worth Star-Telegram, 17 Oct. 2026

Deputies entered the home Friday morning after efforts to persuade Mullennix to surrender were unsuccessful. — Sacbee.com, 17 Oct. 2026

Word History

First Known Use

1617, in the meaning defined above

Phrases Containing unsuccessful

• make an unsuccessful run for

Rhymes for unsuccessful

• distressful
• successful
• stressful

Kids Definition

unsuccessful

adjective

un·​suc·​cess·​ful ˌən(t)-sək-ˈses-fəl 

: not successful : not having or producing success

unsuccessfully

-fə-lē 

adverb