know better

Idioms

Be able to recognize something as wrong or not possible, as in Mary should know better than to leave her child alone in the house, or Try to get in without a ticket? You know better than that. [c. 1700]

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Churches know better than to hold a second collection every Sunday to cover ordinary expenses, because parishioners may get tired of giving.

From The Wall Street Journal • Jun. 7, 2026

They know better than anyone that waiting for justice is a frustrating experience.

From BBC • Jun. 3, 2026

This keeps happening, even to people who should know better.

From Barron's • Apr. 29, 2026

The movie is simultaneously more depressing than the original and more saccharine, with a repellent amount of affection between characters who should know better.

From Los Angeles Times • Apr. 29, 2026

"You know better than that," said the young monk sternly.

From "A Wish in the Dark" by Christina Soontornvat

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023