Merriam-Webster's Word of the Day for May 10, 2026 is:

halcyon • \HAL-see-un\  • adjective

Halcyon is most often used to describe a happy and successful time in the past that is remembered as being better than today. It can also mean “calm, peaceful” or “prosperous, affluent.”

// She does not regret retiring, but looks back fondly on the halcyon years of her career.

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Examples:

“The first half of Alice Winn’s bestselling In Memoriam is set at Preshute, an English boys’ boarding school in the early twentieth century. It is here, in the idyllic countryside, where the boys discuss poetry and get up to all sorts of high-jinks and japes, and where two students, Gaunt and Ellwood, fall in love. Then the boys are ejected into the horror and abyss of WWI trenches. When they are reunited, mentally and physically scarred, Preshute is but a dream and their adolescent love, a halcyon place that can only be returned to in memory.” — Madeleine Dunnigan, LitHub.com, 16 Jan. 2026

Did you know?

Halcyon has drifted along contentedly in English for centuries, but it hatched from a tumultuous story. According to Greek mythology, Alkyone, the daughter of the god of the winds, became so distraught over her husband Ceyx’s death at sea that she threw herself into the ocean to join him. The gods were moved by the couple’s love, and took pity on them by turning them into halcyon birds, a bird identified with the kingfisher. (Kingfishers are known for plunging into water after prey.) According to the legend, the birds built their nests on the sea, which so charmed Alkyone’s father that he created a period of unusual calm that lasted until the birds’ eggs hatched. Our word halcyon reflects the story in multiple ways. When halcyon was first used in English in the 14th century it was as a noun referring to the mythical bird, and later to actual kingfishers as well. Adjective use developed in the 16th century and now most often evokes those calm waters: the word typically describes an idyllic time in the past.