We found 15 dictionaries that define the word involuntary muscle:

General (9 matching dictionaries)

1. involuntary muscle: Merriam-Webster
2. involuntary muscle: Vocabulary.com
3. involuntary muscle: Wiktionary
4. involuntary muscle: Dictionary.com
5. Involuntary muscle: Wikipedia, the Free Encyclopedia
6. involuntary muscle: Rhymezone
7. involuntary muscle: FreeDictionary.org
8. involuntary muscle: Mnemonic Dictionary
9. involuntary muscle: TheFreeDictionary.com

Business (1 matching dictionary)

10. involuntary muscle: Legal dictionary

Computing (1 matching dictionary)

11. involuntary muscle: Encyclopedia

Medicine (4 matching dictionaries)

12. involuntary muscle: Merriam-Webster Medical Dictionary
13. Dorland's Illustrated Medical Dictionary (No longer online)
14. KidsHealth Glossary of Medical Words (No longer online)
15. involuntary muscle: Medical dictionary

(Note: See involuntary_muscles as well.)

Definitions from Wiktionary (involuntary muscle) ▸ noun:  (anatomy) A muscle that is not controlled by individual volition, e.g., cardiac muscle and smooth muscle. Similar: smooth muscle, noncardiomyocyte, nonmyocyte, nonelective, nonmoving part, nonhypervascularity, invertibrate, inanimate, servile, unaccusative, more... Opposite: voluntary, striated, skeletal Types: smooth muscle, skeletal muscle, cardiac muscle, striated muscle, more... Phrases: involuntary muscle contraction, more... Adjectives: spastic, atonic, monoplegic, paralytic, katatonic, eutonic, palsied, catatonic, epitonic, sciatic, athetoid ▸ Words similar to involuntary muscle ▸ Usage examples for involuntary muscle ▸ Idioms related to involuntary muscle ▸ Wikipedia articles (New!) ▸ Words that often appear near involuntary muscle ▸ Rhymes of involuntary muscle ▸ Invented words related to involuntary muscle