unbelievable
Americanadjective
-
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
- unbelievability noun
- unbelievably adverb
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.
“I’m just not threatened by it . . . Ten years ago, I would have needed to engage a visual effects house at an unbelievable cost to come up with this stuff,” he said.
From Salon • Apr. 17, 2026
Benjamin described the response to his performance as "unbelievable" and said he had since received calls from producers of BBC One's The Voice UK and ITV's Britain's Got Talent.
From BBC • Apr. 16, 2026
Defensively, they held Texas star Madison Booker to three baskets off 23 attempts, including an unbelievable 17 straight misses at one point.
From Los Angeles Times • Apr. 4, 2026
“It’s a lot of knowledge workers doing similar tasks with data, an unbelievable distribution network” that reaches institutional investors around the globe.
From Barron's • Apr. 3, 2026
Yep, it’s incredible, amazin’ and unbelievable, but the li’l fellers do occasionally catch the best end of the stick.
From "Friday Night Lights: A Town, A Team, And A Dream" by H.G. Bissinger
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.
