decades

IPA/ˈdek.eɪd/
KK[dˈɛkedz]IPA/ˈdek.eɪd/

decades — noun

  • decadessingular
  • decadesesplural

1. A span of ten full years, often named after the starting set of years (such as t

1.nounA2
Definition

A span of ten full years, often named after the starting set of years (such as the 1990s or 2010s) and used especially when describing how things change or develop over a long stretch of time.

Example

Over the past two decades, Abigail's hometown has changed beyond recognition.

over the past + [number] decades (time frame)

Andrés spent three decades learning to make violins by hand.

for + [number] decades (duration)

Common collocations
  • past decade
  • recent decades
  • for decades
  • decades of
  • over the decades
  • the … decade
  • turn of the decade
  • decades-long
Synonyms
  • ten years

    Literal equivalent; less common in formal or journalistic writing ('over the past ten years' rather than 'over the past decade')

  • decennium

    Formal, technical term; very rare in everyday speech

Grammar Patterns

[number] + decades

decades + of + [noun]

over/during + the past/last/recent + [number] + decades

the + [year]s + decade

Usage Note

Often used in the plural (decades) to emphasise a long, indefinite length of time, as in 'for decades' or 'decades of work'. When referring to a specific ten-year span by its number, use 'the' before the year range: 'the 2000s', 'the 1960s decade'. A decade runs from a year ending in 0 to a year ending in 9 — for example, the 1990s decade covers 1990 through 1999, not 1991 through 2000.

Common Mistakes

The 1990s decade ran from 1991 to 2000.
The 1990s decade ran from 1990 to 1999.
A decade starts on a year ending with 0 and ends on a year ending with 9.
They waited for decade.
They waited for a decade.
When using the singular form, include the article 'a' or 'one'.

Word family

  • decade
    nounA2
  • decadal
    adjectiveC1

Synonym discussion

Sense: noun/1

Decade refers specifically to a ten-year span, making it the most precise of these time words. Century covers 100 years and is used for broader historical sweeps ('the 20th century'). Era suggests a stretch of time defined by distinctive events or conditions ('the digital era') rather than a fixed length. Period is the most general — it can mean any length of time ('a period of heavy rain'). Use decade when you want the reader to think of a roughly ten-year span: 'The company grew steadily over a single decade.' Use century for much longer arcs: 'The factory had stood for over a century.' Use era when the defining character matters more than the duration: 'The post-war era brought new jobs to the city.'

decade ↗century ↗era ↗period ↗

Common collocations

Nouns

Phrases

  • for decades to come
  • decades from now
  • over the course of a decade
  • decades on end

Prepositions

Etymology

GreekLatinFrenchEnglish

The word 'decade' entered English in the late 1500s, borrowed from French 'décade', which came from Latin 'decas' (genitive 'decadis'), itself from Greek 'dekas' (a group of ten). The Greek root 'deka' means 'ten'. Originally it could refer to any group of ten things, but over time it became almost exclusively used for a period of ten years.

First known use

15th century

15th century, in the meaning defined at sense 1