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

Cardinal’s campaign follows an unsuccessful bid mounted last spring by a coalition of swim parents that included former Constellation Brands CEO Bill Newlands and his wife Kathy. — Daniel Libit, Sportico.com, 23 July 2026

Advertisement Paul was the lone Republican to vote on multiple previous, unsuccessful war powers resolutions. — Connor Greene, Time, 23 July 2026

Deep Sea Vision previously led an unsuccessful six-month mission in search of Amelia Earhart's plane. — Landon Mion, FOXNews.com, 22 July 2026

By that standard, virtually every use of force short of total conquest will be unsuccessful by definition. — David A. Deptula, Forbes.com, 22 July 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