know-it-all
noun
a person who acts as though they know everything and who dismisses the opinions, comments, or suggestions of others.
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know-it-all
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know it all
know it allsee know all the answers.
know-it-all
American
[noh-it-awl]
/ ˈnoʊ ɪtˌɔl /
noun
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know-it-alls
plural
adjective
know it all
Idioms
Other Word Forms
Noun Inflected Forms
Etymology
Origin of know-it-all
First recorded in 1930–35
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.
See Examples For:
I would admit that having money tends to make you a big know-it-all or arrogant.
From The Wall Street Journal ● Aug. 6, 2026
In a 2015 biography, author Ashlee Vance described Musk as "a confrontational know-it-all" with an "abundant ego".
From BBC ● Jun. 4, 2026
Volker Beck, president of the German-Israeli Society, labelled Steinmeier's comments on the war "grossly inappropriate" and said they displayed a "smug know-it-all attitude".
From Barron's ● Mar. 24, 2026
I have been a know-it-all Dodger fan since the late 1950s and after last season I thought, and hoped, Clayton Kershaw would retire.
From Los Angeles Times ● Sep. 20, 2025
Well, anyway, he's a know-it-all and he walks on his toes, but he's the only boy around.
From "What the Night Sings" by Vesper Stamper
His character development transitions from a justified frustration to the conclusion that humans behaving as though they know it all is the ultimate act of hubris.
From Los Angeles Times ● Sep. 10, 2025
A voyager is curious and open to the idea that they don’t know it all.
From Slate ● Jan. 14, 2024
"It's just very painful not to know those things when those 18 Reuzegom defendants know it all," Mr De Vel said.
From BBC ● Jun. 2, 2023
Lansbury was wise without being a know-it-all, even though she did actually know it all.
From Salon ● Oct. 12, 2022
“Yeah, you don’t think you are. But it’s always the smart ones, the ones who know it all, who make the most mistakes.”
From "As Brave As You" by Jason Reynolds
The latter’s proxy was city controller Kenneth Mejia, another person loathed by L.A.’s political know-it-alls because he keeps bucking it.
From Los Angeles Times ● Oct. 14, 2026
Soft know-it-alls from the city and phonies of any stripe receive rough treatment in his shows, such as the llama farmer from California who gets thrown under a Montana cattle guard in “Yellowstone.”
From The Wall Street Journal ● Oct. 31, 2025
I like this exercise because it’s not a recounting by news know-it-alls.
From Seattle Times ● Dec. 28, 2023
We now live in a world of know-it-alls, catalyzed by a social media engine that brings these forces together.
From Washington Post ● Jan. 26, 2022
“I don’t think Raven actually hid this book. She’s probably one of those know-it-alls who likes to flaunt every fact in her head. Yippee for you, you know a lot about Edgar Allan Poe.”
From "Book Scavenger" by Jennifer Chambliss Bertman
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Get a wordDefinitions 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.
