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.
Rooney would also start James on the right side of defence this summer, despite calling the 26-year-old "unreliable" as a full-back.
From BBC • May 8, 2026
“This letter shows that even utilities like CenterPoint admit that there is no grid emergency and that coal plants are too unreliable, expensive, and polluting to continue operating,” said Ben Inskeep, the coalition’s program director.
From Barron's • Apr. 20, 2026
"Although MFCs have existed as a concept for more than a century, their unreliable performance and low output power have stymied efforts to make practical use of them, especially in low-moisture conditions," Yen said.
From Science Daily • Apr. 19, 2026
“LLMs themselves are more or less just as unreliable as they were ever,” says AI researcher and gadfly Gary Marcus.
From The Wall Street Journal • Apr. 17, 2026
I had been south as far as Wakefield; beyond that, my geography was unreliable.
From "The Shakespeare Stealer" by Gary L. Blackwood
Definitions 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.
