unreliable
Americanadjective
adjective
Other Word Forms
Etymology
Origin of unreliable
Explanation
Someone unreliable can't be trusted to do something. Things can be unreliable too, like a bike with a wobbly wheel. The word "rely" is a clue to what unreliable means. When you can rely on something, you can count in it — it's reliable. On the other hand, you'd better not count on an unreliable person. People can be unreliable because they're dishonest, always late, bad at their job, or just inconsistent. Things can be unreliable because they're broken or old. A train schedule can be unreliable if the trains are never on time. Unfortunately, there's a lot of stuff in life that's unreliable, so be careful.
Vocabulary lists containing unreliable
STAAR English I: Elements of Literature
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STAAR English II: Elements of Literature 1
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Point of View
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Around the same time, the ticket machines were proving similarly unreliable about accepting credit cards.
From Salon ● Oct. 17, 2026
The findings also demonstrate why scientists must draw on several independent methods when reconstructing population histories, particularly when written records are incomplete, unreliable, or shaped by historical biases.
From Science Daily ● Oct. 14, 2026
OpenAI canceled the release of a new model, Astra 6.1, because it deemed the model unreliable and found that it frequently ignored instructions.
From Barron's ● Oct. 2, 2026
Johal's family say no concrete evidence has been presented against him and that the case was built on the testimony of unreliable witnesses.
From BBC ● Oct. 1, 2026
“That’s unacceptable. You’re the ones who sent the postcard and you must have known how unreliable the mail is. I insist on speaking with my sister.”
From "The Dead and the Gone" by Susan Beth Pfeffer
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Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
