noun
oxygen mask
A mask worn over the nose and mouth to supply oxygen, used in medical, aviation, and emergency contexts.
患者に酸素マスクを装着した。
I put an oxygen mask on the patient.
機内で酸素マスクが降りてきた。
The oxygen masks dropped down inside the cabin.
Compound of 酸素 (sanso, 'oxygen') and マスク (masuku, from English 'mask').