know-it-all

[ noh-it-awl ]
See synonyms for know-it-all on Thesaurus.com
noun
  1. a person who acts as though they know everything and who dismisses the opinions, comments, or suggestions of others.

adjective
  1. of or characteristic of a person who acts as though they know everything and who dismisses the opinions, comments, or suggestions of others.

Origin of know-it-all

1
First recorded in 1930–35

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use know-it-all in a sentence

  • Lewis was one of these stuck-up, know-it-all johnnies, not long breeched.

    Two on the Trail | Hulbert Footner
  • "I've a good mind not to tell you, Mr. know-it-all," exclaimed Johnny Chuck.

    The Adventures of Reddy Fox | Thornton W. Burgess
  • None of the new girls appeared to be inclined toward a “know-it-all” attitude, for which Jane was grateful.

  • They couldn't fool me with their slick off-the-cuff ready-made know-it-all responses!

    The Capgras Shift | Sam Vaknin
  • "She is—and she's just what you need," said Sue, with that know-it-all smile of hers.

    The Harbor | Ernest Poole

Other Idioms and Phrases with know-it-all

know-it-all

see know all the answers.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.