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

Morningstar calculated last year that Ark Innovation was the top value-destroying active ETF of the past decade, losing owners nearly $7 billion.

From The Wall Street Journal • Apr. 17, 2026

Herring has been making food content for a decade, but nothing has captivated her audience as much as this most recent series.

From BBC • Apr. 17, 2026

A decade after that career highlight, Cheap Trick has no intention of hanging up the guitars or putting down the mic.

From Los Angeles Times • Apr. 17, 2026

Beijing has alienated most of the other European partners it courted through the so-called 17+1 initiative a decade ago, notes Dimitar Lilkov, a senior research officer at the Wilfried Martens Centre for European Studies.

From Barron's • Apr. 17, 2026

Most of the black pages are filled with articles clipped from newspapers, but there are also handwritten letters, the dates ranging from only a few years previous to more than a decade ago.

From "The Night Circus" by Erin Morgenstern