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

There are several advanced monitoring components: • Outlier Detection: Flags anomalous predictions that may be unreliable for production use, particularly important given the noisy nature of real-world data. —Neel Sendas, Forbes.com, 4 Apr. 2025

Is Demko too unreliable with his health that his cap hit would be better spent upgrading the forward group? —Harman Dayal, New York Times, 3 Apr. 2025

To be sure, these predictions are notoriously unreliable, but the fact remains that Wall Street, which cheered Trump’s election, is losing faith. —John Cassidy, New Yorker, 3 Apr. 2025

The ethics of threatening the victim of aggression apart, if SpaceX proves to be an unreliable provider we will be forced to look for other suppliers. —Jason D. Greenblatt, MSNBC Newsweek, 2 Apr. 2025

Word History

First Known Use

1810, in the meaning defined above

Rhymes for unreliable

• leviable
• reliable
• classifiable
• justifiable
• modifiable
• notifiable
• satisfiable
• specifiable
• undeniable
• verifiable
• emulsifiable
• identifiable