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

The PhD student described herself as naturally a "spontaneous person" but said often she is so exhausted she fears cancelling dates may give the wrong impression that she's unreliable or worse, uninterested.

Read more on BBC

While much of the business-side data can be reconstructed, officials say, the household survey, which relies on reaching people directly, was impossible to conduct retroactively without risking unreliable results.

Read more on Salon

Their meetings acquired the flavor of a postmodern literary puzzle: The story rang true even as the narrator seemed entirely unreliable.

Read more on Literature

Russian state statistics are unreliable, but even they show recent increases in gasoline prices.

Read more on The Wall Street Journal

But she also recently revealed in a Vanity Fair lie detector test that she failed a few exams along the way, blaming ChatGPT for being an unreliable study buddy.

Read more on Salon

Related Words

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