First recorded in 1930–35
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Sandwiched between his rebellious older brother, Dylan, and his know-it-all younger brother, Miles, Felix finds it easier to ignore the world around him.
From The Wall Street Journal ● Jun. 12, 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
Of course, being a kid is full of trial and error, especially when you’re a know-it-all.
From Salon ● Mar. 2, 2025
The last person I need to see right now is a know-it-all grim reaper.
From "Saints and Misfits" by S.K. Ali
This is a young woman who wants to know it all.
From Salon ● Jun. 9, 2025
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
"The 15-year-olds aren't impressed - they know it all at that age."
From BBC ● Jan. 31, 2023
It’s weird: This whole time I had been thinking about Auggie like he was my enemy, but when Grandmère told me that story, I don’t know, it all kind of just sank in with me.
From "Auggie & Me" by R. J. Palacio
For a nation that still gets diminished as a soccer outsider, the U.S. sure produces a lot of soccer know-it-alls, and the men get a lot of unsolicited wisdom from the homeland.
From The Wall Street Journal ● Jun. 13, 2026
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.
