unreliable

adjective

un·​re·​li·​able ˌən-ri-ˈlī-ə-bəl How to pronounce unreliable (audio)
: not reliable : undependable, untrustworthy
an unreliable friend
an unreliable source of funding
an unreliable car
unreliability noun
the unreliability of the data
a person with a reputation for unreliability
unreliably adverb
a method that works unreliably

Examples of unreliable in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
This approach is unreliable because the proxy materials, like volcanic rock, might have been changed by geological processes or created long after the eggs were laid, resulting in incorrect age estimates. Mrigakshi Dixit, Interesting Engineering, 11 Sep. 2025 Everyone knew taxis were an unreliable and largely unlovable service. David Malcolm, Forbes.com, 11 Sep. 2025 The latter approach, often based on mass scraping of the internet, is already producing American chatbots with false and unreliable results, including the parroting of Chinese Communist Party propaganda in response to consumer queries. Ruth Vitale, Deadline, 10 Sep. 2025 Aiding Ukraine has already begun to be a controversial subject in Poland; the prospect of Russian attacks in retaliation could drive up opposition, especially if the United States proves unreliable. Robert Kagan, The Atlantic, 10 Sep. 2025 See All Example Sentences for unreliable

Word History

First Known Use

1810, in the meaning defined above

Time Traveler
The first known use of unreliable was in 1810

Browse Nearby Words

Cite this Entry

“Unreliable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unreliable. Accessed 12 Sep. 2025.

More from Merriam-Webster on unreliable

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!