noun
trillion
The number 1,000,000,000,000 in modern English short-scale usage.
Where it comes from
Trillion ordinarily means the number 1,000,000,000,000 in modern English short-scale usage. Trillion was built in the French large-number system from tri- and the ending of million. In Nicolas Chuquet's fifteenth-century long scale, the prefix marked the third power of a million: 10^18. A competing short scale advanced each -illion name by thousands, making trillion 10^12.
How the meaning developed
American English adopted that value, and it is now standard across English, but long-scale languages still use cognate words for 10^18.
Sources
- Trillion Definition & Meaning
- What is a billion? And other large numbers
- Earliest Known Uses of Some of the Words of Mathematics (M)
Definitions adapted from Open English WordNet where applicable. License and attribution. Word-history text comes from Lexifour’s sourced social research; pages are assembled automatically, not individually fact-checked on every update.
Updated 2026-10-05. Report a correction.