decade

American  

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

noun

decades plural

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

Derived Forms

• half-decade
  noun
• decadal
  adjective

Inflected Forms

Nouns

• decades
  plural

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

The traces of the earlier structure were found a decade ago in Bulford when the ground was cleared for new army housing.

From BBC • Jun. 17, 2026

Barron’s selected Microsoft as a stock pick in March, arguing the stock was at its cheapest level in a decade.

From Barron's • Jun. 17, 2026

He said the company has offtake agreements signed into the next decade.

From The Wall Street Journal • Jun. 17, 2026

The 10-year rule is forcing inherited traditional retirement accounts to be emptied within a decade.

From MarketWatch • Jun. 17, 2026

Over the course of the decade, a series of space missions confirmed that the idea of having a launch vehicle that separated from the mother ship would, in fact, work.

From "Reaching for the Moon" by Katherine Johnson