A know it all is someone who thinks they know everything, and refuses to take anyone else's opinion into consideration because, naturally, they know it all. Also known as a Brian.
I have green eyes but my boyfriend Brian insists that I have hazel eyes. Clearly he is a know it all.
by Arniverna September 9, 2022
Get the Know it allmug. A name given to a person that expresses basic common knowledge about a subject, by a person that doesn't know shit about fuck on said subject.
Me: Hey Edgar, maybe you should just check to see if the outlet is blown before you start taking apart the DJ's mixing board.
Edgar: Oh dang man, that actually worked! Quit being such a know-it-all, you're making me look bad.
Edgar: Oh dang man, that actually worked! Quit being such a know-it-all, you're making me look bad.
by Methkateer December 22, 2023
Get the Know-it-allmug. He knows it all 👀. Made by the Grimm brothers as a Grimm fairytale but could pass as a porno name (someone please make this Im being held hostage)
by Dickhead extreme March 3, 2020
Get the doctor know it allmug. A lot of people confused the guy with a know it all. He didnt think he had all the answers to everything, but he was sure of which ones were bullshit.
by Solid Mantis June 9, 2020
Get the Know it allmug. Governor So-Know-It-All was a general contractor in NH.
by Coop Dupe December 1, 2022
Get the Governor So-Know-It-Allmug.