un·​re·​li·​able | \ ˌən-ri-ˈlī-ə-bəl How to pronounce unreliable (audio) \

Definition of unreliable

: not reliable : undependable, untrustworthy an unreliable friend an unreliable source of funding an unreliable car

Other Words from unreliable

unreliability \ ˌən-​ri-​ˌlī-​ə-​ˈbi-​lə-​tē How to pronounce unreliable (audio) \ noun
the unreliability of the data a person with a reputation for unreliability
unreliably \ ˌən-​ri-​ˈlī-​ə-​blē How to pronounce unreliable (audio) \ adverb
a method that works unreliably

Examples of unreliable in a Sentence

Recent Examples on the Web College kickers can be so unreliable that just those two words are a meme in college football social media circles. Adam Lichtenstein, Sun Sentinel, 11 Sep. 2022 As a result, Europe has become ever more dependent on wind and solar—which are too unreliable to power advanced industrial economies—while perversely eschewing nuclear power. The Editorial Board, WSJ, 8 Sep. 2022 Cooling systems and other mechanisms that are essential to the safe operation of the reactors need power to run them, while emergency diesel generators are sometimes unreliable. Yuliya Talmazan, NBC News, 26 Aug. 2022 The more immediate concern is that a disruption of electricity supply to the plant could knock out cooling systems that are essential for the safe operation of the reactors, and emergency diesel generators are sometimes unreliable. Frank Jordans And Hanna Arhirova, Anchorage Daily News, 25 Aug. 2022 Turgenev was also indecisive, inconstant, maybe even a bit unreliable. Keith Gessen, The New Yorker, 29 Aug. 2022 When Glyn’s unreliable (and indifferent) husband blew their finances through excessive drinking and gambling, Glyn found that what had begun as a diversion needed to become her livelihood. Jeanine Basinger, WSJ, 12 Aug. 2022 No forensic evidence linked Mr. Woodfox to the crime, so the authorities’ argument depended on witnesses, who over time were discredited or proved unreliable. New York Times, 5 Aug. 2022 The original concept, as founded in 1978, was to send email over FM radio subcarriers, but the technology proved unreliable. Cameron Kaiser, Ars Technica, 4 Aug. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'unreliable.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of unreliable

1810, in the meaning defined above

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Time Traveler for unreliable

Time Traveler

The first known use of unreliable was in 1810

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Last Updated

15 Sep 2022

Cite this Entry

“Unreliable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unreliable. Accessed 28 Sep. 2022.

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More Definitions for unreliable


un·​re·​li·​able | \ ˌən-ri-ˈlī-ə-bəl \

Kids Definition of unreliable

: not worthy of trust He got rid of his unreliable car.


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