billion

IPA/ˈbɪljən/
KK[bˈɪljən]IPA/ˈbɪljən/

billion — number

1. the whole number written as 1,000,000,000 — that is, a thousand groups of one mi

1.numberB2
Definition

the whole number written as 1,000,000,000 — that is, a thousand groups of one million.

Example

Earth is home to about eight billion people in 2024.

number + billion + plural noun

The new bridge in Tokyo cost nearly two billion dollars to build.

billion + currency + plural noun

Common collocations
  • a/one billion dollars
  • two billion years
  • billion-dollar industry
  • nearly a billion
  • over a billion

Grammar Patterns

a/one billion + plural noun

number + billion + plural noun

Usage Note

Always followed by a plural noun without 's' on 'billion' itself: 'two billion dollars', NOT 'two billions dollars'. The plural form 'billions' only appears in sense 2 (with 'of').

Common Mistakes

The project cost three billions dollars.
The project cost three billion dollars.
when a specific number comes before, 'billion' stays singular.
There were billion of stars.
There were billions of stars.
without a specific number, use plural 'billions of'.

2. an extremely large but not exact amount, used as exaggeration to stress how huge

2.numberB2
Definition

an extremely large but not exact amount, used as exaggeration to stress how huge a quantity feels.

Example

Nikolai said he had told his sister to clean her room billions of times.

billions of + plural noun for exaggeration

On clear desert nights, you can see billions of stars above your head.

billions of + plural noun

Common collocations
  • billions of stars
  • billions of times
  • billions and billions
  • billions of dollars
Synonyms
  • millions

    smaller-feeling exaggeration; 'millions of' is slightly less extreme than 'billions of'.

  • tons

    informal, used for both countable and uncountable things; 'tons of homework' but only 'billions of stars'.

  • loads

    very informal British English; not used for stars, planets, or scientific contexts.

Antonyms
  • a handful

    the opposite idea — only a few items.

Grammar Patterns

billions of + plural noun

billions and billions of + plural noun

Usage Note

Always plural ('billions of') in this sense, never 'a billion' or 'one billion'. Sounds informal and emotional; in formal writing, prefer 'a huge number of' or give a real figure.

Common Mistakes

I have one billion of emails to read.
I have billions of emails to read.
for exaggeration, use plural 'billions of', not 'one billion'.
The forest had billions trees.
The forest had billions of trees.
'of' is required before the noun in this sense.

3. a real but rough quantity in the range of several thousand million up to nearly

3.numberB2
Definition

a real but rough quantity in the range of several thousand million up to nearly a million million, used when the speaker means an actual large figure rather than a wild guess.

Example

The oil company earned billions of dollars during the war years.

billions of + currency in finance

The Brazilian government spent billions of reais on the new highway network.

billions of + currency

Common collocations
  • billions of dollars
  • billions of pounds
  • billions of euros
  • spend billions
  • lose billions
  • worth billions
Synonyms
  • billions of

    same range; this is the standard form used with currency and countable nouns.

Grammar Patterns

billions of + currency

billions of + countable plural noun

Usage Note

Subject is often a company, government, or industry. Distinguish from sense 2: this sense gives a real (if rough) numerical scale; sense 2 is pure exaggeration. If the speaker means an actual financial figure, this is the sense in play.

Common Mistakes

The deal is worth a few billion of dollars.
The deal is worth a few billion dollars.
drop 'of' when a number like 'a few' or 'several' comes first.

4. in older British texts, the number written as 1,000,000,000,000 — equal to a mil

4.numberC2
Definition

in older British texts, the number written as 1,000,000,000,000 — equal to a million millions, the same value modern English now calls a trillion.

Example

In a Victorian textbook, Professor Hayes found that 'one billion' meant a million million.

older British meaning of 'one billion'

At the London archive, Dr. Patel held a 1950s ledger where 'two billion pounds' meant two million million.

historical British definition in archive context

Common collocations
  • older British 'billion'
  • pre-1974 British usage
Synonyms
  • trillion

    the modern English word for the value (1,000,000,000,000) this older sense names.

Usage Note

Almost no one uses this meaning today. Modern British English follows the American value (1,000,000,000) for 'billion'. Distinguish from sense 1: this older sense is only relevant when reading old UK documents.

Common Mistakes

In modern UK news, a billion still means a million million.
In modern UK news, a billion means a thousand million.
Britain switched to the American value decades ago.

billion — noun

Word family

Synonym discussion

Sense: number/1

In modern English, 'a billion' equals a thousand million (1,000,000,000) on both sides of the Atlantic. 'Thousand million' is the older British phrasing — clearer in technical or historical writing where readers might wonder which 'billion' is meant, but it sounds heavy in everyday speech. 'Trillion' is the next step up: a thousand billions, written as 1,000,000,000,000. Confusing the two by a factor of a thousand is a very common error in news translation. 'Milliard' is the standard word for 1,000,000,000 in French, German, and many other European languages, and it sometimes appears in old English economics texts to avoid the British–American billion confusion. So Camille's company hitting 'a billion users' would be 'a thousand million users' in old British style, but never a 'trillion' or a 'milliard' in modern American or British English news.

billion ↗thousand milliontrillion ↗milliard

Common collocations

Nouns

Adverbs

Phrases

  • a billion-dollar industry
  • billions and billions
  • in the billions
  • worth billions
  • make billions
  • lose billions
  • billions of times

Prepositions

  • of (billions of stars)
  • in (in the billions)
  • to (one to two billion)
  • from (from billions to trillions)

Etymology

FrenchEnglishAmerican English

'Billion' was put together in 16th-century French from 'bi-' (meaning 'two') plus the ending of 'million', to name a million raised to the second power — that is, a million millions. English borrowed the word in the 1680s with this larger sense. By the 19th century, American usage shifted it down to a thousand million, partly to match the simpler way of naming each new group of three zeros. Britain held on to the older value until the 1970s, when official UK usage adopted the American figure to keep international finance and science writing consistent. The older British meaning still turns up in pre-1974 documents and is the reason 'thousand million' is sometimes preferred for absolute clarity.