We found 20 dictionaries that define the word mates:

General (12 matching dictionaries)

1. mates: Merriam-Webster
2. mates: Vocabulary.com
3. Mate's, Mates, mate's, mates: Wordnik
4. mates: Cambridge Advanced Learner's Dictionary
5. mates: Wiktionary
6. mates: Cambridge Essential American English Dictionary
7. Mates: Wikipedia, the Free Encyclopedia
8. mates: Rhymezone
9. mates: FreeDictionary.org
10. mates: Mnemonic Dictionary
11. -mates, mates: TheFreeDictionary.com
12. mates: Dictionary.com

Business (1 matching dictionary)

13. -mates, mates: Legal dictionary

Computing (1 matching dictionary)

14. -mates, mates: Encyclopedia

Medicine (2 matching dictionaries)

15. mates: Merriam-Webster Medical Dictionary
16. -mates, mates: Medical dictionary

Miscellaneous (3 matching dictionaries)

17. MATES: Acronym Finder
18. AbbreviationZ (No longer online)
19. -mates, mates: Idioms

Slang (1 matching dictionary)

20. Mates, The Mates: Urban Dictionary

(Note: See mate as well.)

Definitions from Wiktionary (Mates) ▸ adjective:  Friendly; having a friendship (with). ▸ noun:  A surname. Similar: couple, match, friendful, friendly, companionate, friendshiply, amical, friendsome, friendshipy, amicable, more... Opposite: enemies, opponents, foes Types: best mates, buddies, more... Phrases: soul mates, age mates, running mates, team mates, school mates, more... Adjectives: potential, age, team, class, old, school, own, prospective, former, female, male ▸ Words similar to mates ▸ Usage examples for mates ▸ Idioms related to mates ▸ Wikipedia articles (New!) ▸ Popular adjectives describing mates ▸ Popular nouns described by mates ▸ Words that often appear near mates ▸ Rhymes of mates ▸ Invented words related to mates