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.
"But this is to forget that the second goal was just spectacular - almost unbelievable."
From BBC ● Jul. 12, 2026
His movement for his first goal against Brazil was just unbelievable.
From BBC ● Jul. 8, 2026
Plus, to imagine the streamer will keep digging deeper into live sports without one day also adopting live news seems unbelievable.
From The Wall Street Journal ● Jun. 30, 2026
"It was unbelievable, I don't even know how long it lasted," said shopkeeper Heidi Romero, who was on the top floor of the shopping center when the quake struck.
From Barron's ● Jun. 25, 2026
Looking at him from such close range, it strikes me now with certainty that it’s not the first time I’ve laid eyes on this totally unbelievable guy.
From "I'll Give You the Sun" by Jandy Nelson
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.
