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:
But it’s voters who decide elections, not know-it-all columnists.
From Los Angeles Times ● Jun. 7, 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
The idea was to put to rest any worry that she might parade in like a know-it-all.
From The Wall Street Journal ● Oct. 30, 2025
Roland Mathers, who is kind of a know-it-all and talks like he’s forty, raises his hand and starts to speak even before she calls on him.
From "Finding Junie Kim" by Ellen Oh
As we know, it all became moot when President Gerald Ford pardoned Nixon.
From Salon ● Feb. 9, 2024
A voyager is curious and open to the idea that they don’t know it all.
From Slate ● Jan. 14, 2024
Virgos are like, “I know it all even if I’m wrong.”
From Los Angeles Times ● Jun. 23, 2023
"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
And fore I know it, all three kids is playing in there, splashing around, having a good old time.
From "The Help" by Kathryn Stockett
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
It also has a user base heavy with designers, photographers, and know-it-alls, and even just redesigning the app’s logo has been known to send them into fits.
From The Verge ● Sep. 10, 2020
We are also both incredibly stubborn and principled know-it-alls.
From Slate ● Jun. 7, 2020
“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
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.
