unreliable

adjective

un·​re·​li·​able ˌən-ri-ˈlī-ə-bəl 

: not reliable : undependable, untrustworthy

an unreliable friend

an unreliable source of funding

an unreliable car

unreliability

ˌən-ri-ˌlī-ə-ˈbi-lə-tē 

noun

the unreliability of the data

a person with a reputation for unreliability

unreliably

ˌən-ri-ˈlī-ə-blē 

adverb

a method that works unreliably

Examples of unreliable in a Sentence

Recent Examples on the Web

Once the gatekeeping mechanism becomes unreliable, merit is no longer merely difficult to prove. — Penny Abeywardena, Forbes.com, 29 July 2026

One path is a familiar cycle of fiscal strain, unreliable power, and vulnerability to external shocks. — Michael Adu Okyere, Time, 28 July 2026

The leggings were still wet, heavily soiled, and badly deteriorated, LaHendro testified, making the edge detail too unreliable for comparison. — Nancy Dillon, Rolling Stone, 24 July 2026

As code generation becomes more accessible, the ability to identify inaccurate or unreliable outputs may become increasingly valuable. — Felysha Walker, Kansas City Star, 24 July 2026

Word History

First Known Use

1810, in the meaning defined above

Rhymes for unreliable

• liable
• pliable
• triable
• viable
• classifiable
• justifiable
• modifiable
• notifiable
• satisfiable
• specifiable
• undeniable
• verifiable