billion: meaning, definition, pronunciation and examples
B1Formal, semi-formal, informal
Quick answer
What does “billion” mean?
The number equivalent to the product of a thousand and a million.
Audio
Pronunciation
Definition
Meaning and Definition
The number equivalent to the product of a thousand and a million; 1,000,000,000 or 10⁹.
Used hyperbolically to indicate an indefinitely large number or amount.
Dialectal Variation
British vs American Usage
Differences
Historically divergent (long-scale vs. short-scale), but the short-scale meaning (10⁹) is now universally dominant in contemporary UK English for finance, science, and general use. The long-scale meaning (10¹²) is obsolete in modern UK usage but may be encountered in very old texts.
Connotations
Identical in modern usage. No differential connotations.
Frequency
Equally high frequency in both varieties.
Grammar
How to Use “billion” in a Sentence
NUM + billion + of + NP (billions of dollars)a/several/few + billion + NP (a billion people)Vocabulary
Collocations
Examples
Examples of “billion” in a Sentence
adjective
British English
- The billion-pound infrastructure project was approved.
- They faced a billion-to-one chance.
American English
- The billion-dollar lawsuit was settled out of court.
- It was a billion-star hotel.
Usage
Meaning in Context
Business
Used precisely for financial figures, market capitalisation, and budgets (e.g., 'a billion-dollar deal').
Academic
Used in scientific notation, population studies, and astronomy.
Everyday
Used hyperbolically for emphasis (e.g., 'I've told you a billion times').
Technical
A defined numerical quantity (10⁹ or 1,000,000,000) in computing, finance, and statistics.
Watch out
Common Mistakes When Using “billion”
- Using 'billions' as a singular noun (e.g., 'a billions' is incorrect).
- Confusing the order of magnitude with 'million' or 'trillion'.
- Incorrect comma placement in different numbering systems (1,000,000,000 in English).
FAQ
Frequently Asked Questions
Yes. While historically different, the short-scale billion (1,000 million or 10⁹) is now the standard in all English-speaking countries, including the UK, for contemporary use in media, finance, and science.
In the short-scale system, a trillion (10¹²) comes after a billion. In the archaic long-scale system, a milliard (10⁹) came after a billion (10¹²).
2,500,000,000 or 2.5 billion. In scientific notation, it is 2.5 x 10⁹.
Yes, informally it is often used as an exaggerated synonym for 'a very large number', as in 'There were billions of people at the concert'.
The number equivalent to the product of a thousand and a million.
Billion is usually formal, semi-formal, informal in register.
Billion: in British English it is pronounced /ˈbɪl.i.ən/, and in American English it is pronounced /ˈbɪl.jən/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “Thanks a billion! (ironic or emphatic gratitude)”
- “One in a billion (extremely rare)”
- “Feel like a billion dollars (feel excellent)”
Learning
Memory Aids
Mnemonic
Think of 'BI-' as two and 'LLION' sounding like 'lion'. Two lions guarding a mountain of 1,000 stacks of a million coins each.
Conceptual Metaphor
WEALTH IS SIZE / QUANTITY ('a billion-dollar idea'), EXAGGERATION IS MAGNITUDE ('a billion reasons not to go').
Practice
Quiz
In modern standard English, what is the numerical value of 'one billion'?