know–it–all

play
noun \ˈnō-ət-ˌȯl\

Definition of know–it–all

  1. :  one who claims to know everything; also :  one who disdains advice

know–it–all

adjective

1873

First Known Use of know–it–all

1873


KNOW–IT–ALL Defined for English Language Learners

know–it–all

play
noun \ˈnō-ət-ˌȯl\

Definition of know–it–all for English Language Learners

  • : a person who talks and behaves like someone who knows everything


KNOW–IT–ALL Defined for Kids

know–it–all

play
noun \ˈnō-ət-ˌȯl\

Definition of know–it–all for Students

  1. :  a person who always claims to know everything


Learn More about know–it–all


Seen and Heard

What made you want to look up know–it–all? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

a small amount

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

  • winning-words-from-the-national-spelling-bee-logo
  • Which is the correct spelling of the winning word from 1988?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!