Trillion

How to spell trillion

8 letters · 2 syllables

How to pronounce trillion

Say the part in capitals loudest.

What does trillion mean?

1. nounA number equal to a thousand billion, written as one followed by twelve zeros.

Trillion in a sentence

• The national debt has now passed one trillion pounds.

• Astronomers estimate the galaxy holds more than a trillion stars.

Where does trillion come from?

Language of origin: French

Trillion was coined in the sixteenth century by French and Italian mathematicians who were extending the pattern of 'million'. The base 'million' came from the Italian millione, an emphatic enlargement of mille, the Latin word for 'a thousand', so it literally meant 'a great thousand'. To name even larger quantities, scholars stripped 'million' down to its '-illion' tail and bolted on Latin numeral prefixes: bi- (two) gave billion, and tri- (three) gave trillion. English took the word from French in the seventeenth century. A historical quirk is that trillion long meant different amounts on each side of the Atlantic: the older British 'long scale' counted it as a million million, while the American 'short scale' counted it as a thousand million million; today both regions generally use the American value. The double 'l' that trips writers up is inherited straight from 'million', where it has always sat.

How the word is built

• tri- (three)
• -illion (large-number ending modelled on 'million')