We found 18 dictionaries that define the word martial arts:

General (11 matching dictionaries)

1. martial arts: Merriam-Webster
2. martial arts: Oxford Learner's Dictionaries
3. martial arts: Collins English Dictionary
4. martial arts: Vocabulary.com
5. martial-arts: Wordnik
6. martial arts: Cambridge Advanced Learner's Dictionary
7. martial arts: Wiktionary
8. martial arts: Infoplease Dictionary
9. martial arts: Dictionary.com
10. Martial Arts, Martial-arts, Martial arts (genre), Martial arts: Wikipedia, the Free Encyclopedia
11. Martial arts: TheFreeDictionary.com

Art (1 matching dictionary)

12. Movie Terminology Glossary (No longer online)

Computing (1 matching dictionary)

13. Martial-arts, martial arts: Encyclopedia

Medicine (3 matching dictionaries)

14. Medical Dictionary (No longer online)
15. online medical dictionary (No longer online)
16. Martial-arts, martial arts: Medical dictionary

Science (1 matching dictionary)

17. martial arts: LITTLE EXPLORERS(TM) Picture Dictionary

Slang (1 matching dictionary)

18. Martial Arts: Urban Dictionary

(Note: See martial_art as well.)

Definitions from Wiktionary (martial arts) ▸ noun:  Collectively, the traditional East Asian fighting styles, and their derivatives Similar: wushu, Wing Chun, budo, eskrima, Tang Soo Do, kumdo, kali, kenpo, kajukenbo, jiang hu, more... Phrases: mixed martial arts, Chinese martial arts, Mixed martial arts weight classes, Martial arts film, Japanese martial arts, more... ▸ Words similar to martial arts ▸ Usage examples for martial arts ▸ Idioms related to martial arts ▸ Wikipedia articles (New!) ▸ Words that often appear near martial arts ▸ Rhymes of martial arts ▸ Invented words related to martial arts