heyday

¹ American  

[hey-dey] / ˈheɪˌdeɪ /

Or heydey

noun

heydays plural

1. the stage or period of greatest vigor, strength, success, etc.; prime.

   the heyday of the vaudeville stars.

2. Archaic. high spirits.

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heyday ² American  

[hey-dey] / ˈheɪ deɪ /

interjection

Archaic.

1. (used as an exclamation of cheerfulness, surprise, wonder, etc.)

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heyday British  

/ ˈheɪˌdeɪ /

noun

1. the time of most power, popularity, vigour, etc; prime

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Other Word Forms

Noun Inflected Forms

• heydays
  plural

Etymology

Origin of heyday¹

1580–90; variant of high day, apparently by confusion with heyday ²

Origin of heyday²

1520–30; rhyming compound based on hey; replacing heyda < German hei da hey there

Explanation

A heyday is a peak of popularity or success. If you hear someone say "Hey! Back in the day, I was the best boxer in the city! No one could beat me!" he might be remembering his heyday as a fighter. If you remember a time in the past when you were doing something really well or getting a lot of attention or fame, you might be reminiscing about your heyday. A person or an organization — and even a thing — can have a heyday, or a peak time when everything goes well. The good news is that a heyday can come again and again, so while your heyday as student president might be just a memory, there might be a heyday as governor of your state years later.

Example Sentences

See Examples For:

heyday heydays

In its 1980s heyday, Japan commanded around half the share of the global semiconductor market.

From Barron's ● Jul. 15, 2026

I don’t know if you know what’s happening, but I’m in the heyday of my career right now.

From Los Angeles Times ● Jul. 2, 2026

Such staffing wasn’t necessary in the heyday of Morley Safer and Mike Wallace, when “60 Minutes” was a money spinner and ratings giant.

From The Wall Street Journal ● Jun. 19, 2026

Tellingly, an apparent nostalgia for Makerfield's coal-mining heyday has featured in Burnham's interviews during the campaign.

From BBC ● Jun. 11, 2026

What's more, the mole's real name was familiar to any spy who had served in Berlin during Bill Harvey's heyday there: For DIOMID, as America now learned, was George Blake.

From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau

In some ways, the current versions of the Seahawks and Patriots are reminiscent of both of their heydays.

From The Wall Street Journal ● Feb. 5, 2026

Volkswagen is trying to tap some of that nostalgia in its latest push to regain the status and sales it enjoyed in the United States during the Beetle’s and Microbus’s heydays in the 1960s.

From New York Times ● Feb. 20, 2024

Rankin, who was once labelled a 'bad boy' celebrity photographer, has mellowed since the Britpop heydays of the noughties and becoming a father.

From BBC ● Jan. 22, 2024

You’ll meet athletic European Millennials wearing multicoloured sunglasses, grey-haired US retirees with epic adventure tales from their ’70s heydays, and everyone else in between — including eager-to-learn alpine virgins like myself.

From National Geographic ● Apr. 16, 2023

Even in heydays of poverty, and poor as she was, you know, notwithstanding our true love for each other, and close intimacy, I never could induce Lucy to receive a cent.

From Miles Wallingford Sequel to "Afloat and Ashore" by Cooper, James Fenimore