Word.ws English Dictionary

-illion

-illion suffix: combined with Latin prefixes for names of integers in order to form names of powers of a million.

Suffix

-illion

  1. Combined with Latin prefixes for names of integers in order to form names of powers of a million.
    • bi- + -illion → billion
    • tri- + -illion → trillion
  2. Added to various nonsense syllables to indicate an arbitrarily very large number.
    • bajillion, gazillion

Origin of -illion

Back-formation from million, then used in billion, trillion, quadrillion, each from French, ultimately from Italian mille (“thousand”) and the augmentative suffix -one. -illion was segmented from million as if mi- was a prefix, and -illion the stem.

Questions about -illion

What does -illion mean?
-illion means combined with Latin prefixes for names of integers in order to form names of powers of a million.
What part of speech is -illion?
-illion is a suffix.

Words near -illion in the dictionary

  1. -ii
  2. -ikin
  3. -ile
  4. -ilide
  5. -illiard
  6. -illion
  7. -ily
  8. -im
  9. -imal
  10. -ime
  11. -imibe

Source and license

Adapted from Wiktionary: -illion (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Cite this entry: “-illion.” Word.ws, https://word.ws/-illion. Based on Wiktionary, CC BY-SA 4.0.