We found 27 dictionaries that define the word zillion:

General (22 matching dictionaries)

1. zillion: Longman Dictionary of Contemporary English
2. zillion: Merriam-Webster
3. zillion: Oxford Learner's Dictionaries
4. zillion: American Heritage Dictionary of the English Language
5. zillion: Collins English Dictionary
6. zillion: Vocabulary.com
7. Zillion, zillion: Wordnik
8. zillion: Cambridge Advanced Learner's Dictionary
9. zillion: Wiktionary
10. zillion: Webster's New World College Dictionary, 4th Ed.
11. zillion: The Wordsmyth English Dictionary-Thesaurus
12. zillion: Infoplease Dictionary
13. zillion: Dictionary.com
14. zillion: Online Etymology Dictionary
15. zillion: Cambridge Essential American English Dictionary
16. Zillion (TV series), Zillion (anime), Zillion (disambiguation), Zillion (video game), Zillion: Wikipedia, the Free Encyclopedia
17. zillion: Rhymezone
18. zillion: FreeDictionary.org
19. zillion: Mnemonic Dictionary
20. zillion: TheFreeDictionary.com

Computing (1 matching dictionary)

21. zillion: Encyclopedia

Science (1 matching dictionary)

22. Zillion: Eric Weisstein's World of Mathematics

Slang (2 matching dictionaries)

23. zillion: Green’s Dictionary of Slang
24. zillion: Urban Dictionary

Sports (1 matching dictionary)

25. zillion: Golfer's Dictionary

(Note: See zillions as well.)

Definitions from Wiktionary ( ) ▸ noun:  (slang, hyperbolic) An unspecified large number (of); a gazillion. Similar: cardinal, a zillion, jillion, jajillion, jazillion, wazillion, squillion, gazillionth, nonillion, umptillion, more... Opposite: zero, none, zip, zilch Types: bazillion, gazillion, jillion, squillion, trillion, quadrillion, quintillion, sextillion, more... Phrases: a zillion, more... ▸ Word origin ▸ Words similar to zillion ▸ Usage examples for zillion ▸ Idioms related to zillion ▸ Wikipedia articles (New!) ▸ Popular adjectives describing zillion ▸ Words that often appear near zillion ▸ Rhymes of zillion ▸ Invented words related to zillion