red-letter

American

[red-let-er] / ˈrɛdˈlɛt ər /

adjective

marked by red letters, as festival days in the church calendar.
memorable; especially important or happy.

a red-letter day in his life.
(of a Bible) having the quoted words of Jesus appear in red type.

a red-letter edition;
the red-letter New Testament presented at her baptism.

Etymology

Origin of red-letter

First recorded in 1660–70

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.

This makes July 10, 2026, the red-letter day because taxpayers usually have three years after filing a return to make a claim disputing a penalty, according to Collins.

From MarketWatch • May 27, 2026

SpaceX’s big news, along with Anthropic’s showing potential to turn a profit far sooner than expected and OpenAI’s prepping for its public debut, made yesterday AI’s red-letter day.

From The Wall Street Journal • May 21, 2026

This was a red-letter day for Adelaide-born Head as he scored a stunning century in front of a packed crowd on familiar territory.

From BBC • Dec. 7, 2024

Could Feb. 15 be a red-letter day for Nikki Haley?

From Washington Times • Feb. 7, 2023

“This is a red-letter day,” my father agrees.

From "Al Capone Does My Shirts" by Gennifer Choldenko

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