decade

American  

[dek-eyd, duh-keyd] / ˈdɛk eɪd, dəˈkeɪd /

noun

1. a period of ten years.

   the three decades from 1776 to 1806.

2. a period of ten years beginning with a year whose last digit is zero.

   the decade of the 1980s.

3. a group, set, or series of ten.

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decade British  

/ dɪˈkeɪd, ˈdɛkeɪd /

noun

1. a period of ten consecutive years

2. a group or series of ten

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Other Word Forms

• decadal adjective
• half-decade noun

Etymology

Origin of decade

First recorded in 1425–75; late Middle English, from Middle French, from Late Latin decad-, stem of decas, from Greek dekás “group of ten”; equivalent to deca- + -ade ²

Explanation

She was so nervous to see her high school sweetheart at their reunion: it had been a decade (ten years) since she'd seen him at graduation, and she still got butterflies thinking about him. A decade is a period of ten years. Decade contains dec, which is used in words that have to do with tens. The Marty Paich Dectet was a band with ten players. A decahedron is a shape with ten faces. And the decimal system is based on the number ten.

Example Sentences

That’s a civilizational re-plumbing on the scale of railroads and electrification combined, compressed into a single decade.

From MarketWatch • Apr. 30, 2026

Over the next decade, cumulative deficits are projected at $24 trillion.

From The Wall Street Journal • Apr. 30, 2026

But Sergio de Sousa, managing partner at Hidden Brook, suggested Essential Quality, a champion colt at 2 and 3 at the start of this decade.

From Los Angeles Times • Apr. 30, 2026

The company's annual profits slid to their lowest level in almost a decade in 2025.

From Barron's • Apr. 30, 2026

Most of them are a good decade younger than me, and this astounds me.

From "Water for Elephants" by Sara Gruen