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.
The lab staff viewed his idea as “a little insane,” one recalled — both unreliable and improper.
From Salon ● Aug. 15, 2026
The cumulative effect of all this was seen at the start of the year, when it became obvious the car and the engine were both uncompetitive and unreliable.
From BBC ● Aug. 4, 2026
According to the complaint, Prabhakar had taught the story for nearly a decade without incident and used it in a unit on unsympathetic and unreliable narrators alongside works by Ernest Hemingway and Raymond Carver.
From Salon ● Aug. 2, 2026
But her biggest fear is for her sick young child, who depends on an oxygen machine powered by unreliable electricity supply.
From The Wall Street Journal ● Jul. 17, 2026
But, as Kuhn also grasped, the fact that even the best-established scientific theories may not endure does not mean that they are unreliable, and it does not mean that science does not progress.
From "The Invention of Science" by David Wootton
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.
