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 industry is currently changing landline services from analogue to digital, with Ofcom describing the copper-based network as "beyond its intended lifespan and increasingly unreliable".

Read more on BBC

Tests for the disease are unreliable, and can lead to men being treated for a slow-growing cancer that is not going to cause them any harm.

Read more on BBC

Corruption remains rampant among state and municipal police, prosecutors and judges in Mexico, often rendering them unreliable partners.

Read more on Los Angeles Times

Increased oil exports to Asia would reduce Canada's economic dependence on an unreliable United States, he said.

Read more on Barron's

Tests for the disease are unreliable, and can lead to men being treated for a slow-growing cancer that isn't going to cause them any harm.

Read more on BBC

Related Words

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