We found 17 dictionaries that define the word zzz:

General (10 matching dictionaries)

1. zzz: Longman Dictionary of Contemporary English
2. zzz: Collins English Dictionary
3. Zzz: Wordnik
4. zzz: Cambridge Advanced Learner's Dictionary
5. zzz: Wiktionary
6. zzz: Webster's New World College Dictionary, 4th Ed.
7. zzz: Dictionary.com
8. ZZZ, ZZz, Zzz: Wikipedia, the Free Encyclopedia

Computing (2 matching dictionaries)

9. ZZZ: Netlingo
10. SMS Dictionary (No longer online)

Medicine (1 matching dictionary)

11. Z.Z.'Z: Medical dictionary

Miscellaneous (3 matching dictionaries)

12. ZZZ: Acronym Finder
13. ZZZ: Three Letter Words with definitions
14. AbbreviationZ (No longer online)

Slang (1 matching dictionary)

15. zzz: Green’s Dictionary of Slang

Definitions from Wiktionary ( ) ▸ verb:  (onomatopoeia) To sleep or snore. Similar: stack z's, snag some z's, snore, zoink, snort, zonk out, somniloquize, somniloquise, saw logs, oscitate, more... Opposite: awake, alert, conscious, vigilant, attentive ▸ Words similar to zzz ▸ Usage examples for zzz ▸ Idioms related to zzz ▸ Wikipedia articles (New!) ▸ Words that often appear near zzz ▸ Rhymes of zzz ▸ Invented words related to zzz