-illion

Origin

Back-formation from {{3}}, billion, trillion, quadrillion, each from French.

Full definition of -illion

Suffix

1. Combined with Latin prefixes for names of integers in order to form names of powers of a million or of a thousand greater than 1,000,000. Thus we have the names billion, trillion, etc.
2. Added to various nonsense syllables to indicate an arbitrarily very large number.

Usage notes

The words formed by combining the Latin prefix for the name of an integer $$

n ($$

n > 1

) with this suffix may mean $$

1,000,000^n or $$

1000^{n + 1} depending on national practices. Hence billion can mean “million million” or “thousand million”. See the usage notes at for more information.

Derived terms