We found 12 dictionaries that define the word zillions:

General (11 matching dictionaries)

1. zillions: Merriam-Webster
2. zillions: Collins English Dictionary
3. zillions: Vocabulary.com
4. Zillions, zillions: Wordnik
5. zillions: Cambridge Advanced Learner's Dictionary
6. zillions: Wiktionary
7. zillions: Dictionary.com
8. zillions: Cambridge Essential American English Dictionary
9. Zillions (magazine): Wikipedia, the Free Encyclopedia
10. zillions: Rhymezone
11. zillions: TheFreeDictionary.com

Slang (1 matching dictionary)

12. zillions: Urban Dictionary

(Note: See zillion as well.)

Definitions from WordNet (zillions) ▸ noun:  a very large indefinite number (usually hyperbole) Opposite: few, handful, limited, scarce ▸ Words similar to zillions ▸ Usage examples for zillions ▸ Idioms related to zillions ▸ Wikipedia articles (New!) ▸ Popular adjectives describing zillions ▸ Words that often appear near zillions ▸ Rhymes of zillions ▸ Invented words related to zillions