unreliable

[uhn-ri-lahy-uh-buhl]

adjective

1. not reliable; not to be relied or depended on.

   Synonyms: untrustworthy, irresponsible, undependable

unreliable

/ ˌʌnrɪˈlaɪəbəl /

adjective

1. not reliable; untrustworthy

   an unreliable witness

Other Word Forms

• unreliability noun
• unreliableness noun
• unreliably adverb

Word History and Origins

Origin of unreliable¹

First recorded in 1830–40; un- ¹ + reliable

Example Sentences

Polls in Argentina have been notoriously unreliable in recent elections, and as we went to press results weren’t yet in.

Read more on The Wall Street Journal

A delayed or unreliable CPI report could complicate Federal Reserve policy decisions, potentially influencing interest rate cuts.

Read more on Barron's

Neither Euroclear nor EU countries want to be seen as unreliable depositories of foreign wealth.

Read more on BBC

Last week, Judge Patrick Lynch rejected an application by defence lawyers to have the case dismissed because they claimed key prosecution evidence was unreliable.

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Mulholland argued that statements made by two key witnesses, Soldiers G and H, who were present in Londonderry that day along with Soldier F, were unreliable and inconsistent.

Read more on Barron's

Related Words

• capricious 
• deceptive 
• dubious 
• false 
• fickle 
• inaccurate 
• irresponsible 
• treacherous 
• tricky 
• uncertain 
• unsound 
• unstable 
• untrustworthy