oxygen mask
nounUK /ˈɒksɪdʒən mɑːsk/
US /ˈɑːksɪdʒən mæsk/
A mask you put over your nose and mouth to breathe in extra oxygen.
The pilot put on her oxygen mask when the plane flew very high.
OTHER MEANINGS
2. A device worn by patients in a hospital to help them breathe.
The nurse adjusted the oxygen mask on the patient's face.
3. Safety equipment used by firefighters or divers in low-oxygen places.
The firefighter wore an oxygen mask inside the smoky building.
4. An emergency mask that drops from the ceiling in an airplane.
Oxygen masks fell from the ceiling when the cabin lost pressure.