We found 24 dictionaries that define the word soundproof:

General (21 matching dictionaries)

1. soundproof: Longman Dictionary of Contemporary English
2. soundproof: Merriam-Webster
3. soundproof: Oxford Learner's Dictionaries
4. soundproof: American Heritage Dictionary of the English Language
5. soundproof: Collins English Dictionary
6. soundproof: Vocabulary.com
7. Soundproof, soundproof: Wordnik
8. soundproof: Cambridge Advanced Learner's Dictionary
9. soundproof: Wiktionary
10. soundproof: Webster's New World College Dictionary, 4th Ed.
11. soundproof: The Wordsmyth English Dictionary-Thesaurus
12. soundproof: Infoplease Dictionary
13. soundproof: Dictionary.com
14. soundproof: Cambridge Essential American English Dictionary
15. Soundproof (album): Wikipedia, the Free Encyclopedia
16. soundproof: Rhymezone
17. soundproof: FreeDictionary.org
18. soundproof: Mnemonic Dictionary
19. soundproof: TheFreeDictionary.com

Computing (1 matching dictionary)

20. soundproof: Encyclopedia

Slang (1 matching dictionary)

21. Soundproof: Urban Dictionary

Tech (1 matching dictionary)

22. Sweetwater Music (No longer online)

(Note: See soundproofed as well.)

Definitions from Wiktionary ( ) ▸ adjective:  Not allowing sound through. ▸ verb:  To make resistant to transmitting sound. Similar: impervious, imperviable, noiseproof, unbreathable, sealed, visionproof, opaque, closed, nonabsorbing, impermeable, more... Opposite: porous, permeable, full of holes Types: material, room, door, window, carpet, blanket, foam, more... ▸ Words similar to soundproof ▸ Usage examples for soundproof ▸ Idioms related to soundproof ▸ Wikipedia articles (New!) ▸ Popular nouns described by soundproof ▸ Words that often appear near soundproof ▸ Rhymes of soundproof ▸ Invented words related to soundproof