Red-letter Day Definition & Meaning - Merriam-Webster

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red-letter day

noun

informal : a very happy and important day

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red-letter red-letter day red-light See all Nearby Words

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“Red-letter day.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/red-letter%20day. Accessed 2 Jan. 2026.

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