We found 10 dictionaries that define the word oxygen masks:

General (7 matching dictionaries)

1. oxygen masks: Merriam-Webster
2. oxygen masks: Collins English Dictionary
3. oxygen masks: Vocabulary.com
4. oxygen masks: Cambridge Advanced Learner's Dictionary
5. oxygen masks: Wiktionary
6. Oxygen masks: Wikipedia, the Free Encyclopedia
7. Oxygen masks: TheFreeDictionary.com

Computing (1 matching dictionary)

8. Oxygen masks: Encyclopedia

Medicine (2 matching dictionaries)

9. oxygen masks: Merriam-Webster Medical Dictionary
10. Oxygen masks: Medical dictionary

(Note: See oxygen_mask as well.)

Definitions from Wiktionary (oxygen mask) ▸ noun:  A plastic or rubber mask through which oxygen may be breathed from a storage tank. ▸ Also see oxygen_mask ▸ Words similar to oxygen masks ▸ Usage examples for oxygen masks ▸ Idioms related to oxygen masks ▸ Wikipedia articles (New!) ▸ Words that often appear near oxygen masks ▸ Rhymes of oxygen masks ▸ Invented words related to oxygen masks