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

But analysts question those claims, which come from unreliable private sources and say voting by non-citizens is extraordinarily rare and has never been shown to have affected any American election. — Dave Goldiner, New York Daily News, 17 July 2026

Mind reading continues to be an unreliable communication strategy. — Valerie Mesa, PEOPLE, 16 July 2026

But Hitchcock also often utilized an unreliable narrator in his storytelling, and Paula seemed to be relatively reliable … right up until the very end. — Erin Qualey, Vulture, 15 July 2026

Connelly did plenty of background on Ball as well, knowing full well his reputation as an unreliable decision-maker. — Jon Krawczynski, New York Times, 15 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