unbelievable
Americanadjective
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too dubious or improbable to be believed.
an unbelievable excuse.
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so remarkable as to strain credulity; extraordinary.
the unbelievable fury of the storm; an unbelievable athlete.
adjective
Other Word Forms
Etymology
Origin of unbelievable
First recorded in 1540–50; un- 1 + believe ( def. ) + -able ( def. )
Explanation
The word unbelievable describes something that is beyond understanding, like the idea, until the Middle Ages, that the earth might actually be round. Unbelievable refers to something that seems incredible (Did you hear the story about the guy who was rescued after being stranded at sea for 6 months on a sailboat?), but it can also refer to something that's so unlikely, so improbable, that you're probably not going to be convinced by it (Hey, did you hear the story about the guy who was rescued after being stranded at sea for 6 months with only a log to keep him afloat?).
Vocabulary lists containing unbelievable
Wow! Synonyms for "Amazing"
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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 answers may come with regret or heartbreak, but they may also come with glorious satisfaction and unbelievable revelations.
From Salon ● Aug. 15, 2026
She added that many of Al Fayed's alleged victims would be distressed by the breach, saying: "For me, it's more of the same, really, and deeply re abusive, to be honest. It's unbelievable."
From BBC ● Aug. 15, 2026
Getting paid to write scripts for a project he’s passionate about, then act out those scripts as a make-believe coach, was once only slightly less unbelievable.
From Los Angeles Times ● Aug. 9, 2026
"I don't have, as unbelievable as it is as mayor of this region, any power to fix this problem, but it doesn't mean I haven't shoved my nose in," she says.
From BBC ● Aug. 7, 2026
Augustus Strong found Kate Fox cute and entertaining but her so-called spirits unbelievable.
From "American Spirits" by Barb Rosenstock
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.
