know-it-all

noun

ˈnō-ət-ˌȯl 

: one who claims to know everything

also : one who disdains advice

know-it-all adjective

Examples of know-it-all in a Sentence

Recent Examples on the Web

White would not be happy about these songs being used to speculate about what goes on behind closed doors — that seems evident enough from the several songs on the album that express enmity toward snoops and know-it-alls. — Chris Willman, Variety, 11 July 2026

Laine MacNeil had her first major role playing Greg Heffley's know-it-all nemesis Patty Farrell in the first three installments of the Wimpy Kid franchise, including Rodrick Rules and Dog Days. — Gillian Telling, PEOPLE, 29 June 2026

His electric Broadway debut as a cocky, yet vulnerable know-it-all just edged Christopher Abbott for the Should prize. — Dalton Ross, Entertainment Weekly, 29 May 2026

Advertisement The most effective leaders are not, in fact, know-it-alls. — Simone Stolzoff, Time, 12 May 2026

Word History

First Known Use

1873, in the meaning defined above

Rhymes for know-it-all

• aerosol
• alcohol
• arbitral
• basketball
• butanol
• cannonball
• carbinol
• cortisol
• ethanol
• fireball
• gasohol
• gossypol

Kids Definition

know-it-all

noun

ˈnō-ət-ˌȯl

: a person who always claims to know everything