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.
Scheduling this service is especially important if your AC is old or unreliable, because the last thing you need is for it to give out during a heat wave.
From MarketWatch • Jun. 29, 2026
"I urge you to reject the evidence of him as wholly incredible and unreliable," he said.
From BBC • Jun. 19, 2026
Choosing depth over volume also matters: one carefully reported long-form article will inform you better than bursts of random, unreliable and emotionally loaded posts on Instagram.
From Science Daily • Jun. 16, 2026
An unnamed Ethiopian assistant professor was selected by ICM for its Midwife Leaders Executive Sponsorship Programme, but was rejected for having an "inadequate financial bank statement and an unreliable purpose of travel", the organisers said.
From Barron's • Jun. 12, 2026
When he found, in managing them, that they were unreliable, disloyal, and dangerous, he got rid of them and turned to his own men.
From "The Prince" by Niccolò Machiavelli
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.
