res ‧ pi ‧ ra ‧ tor /ˈrespəreɪtə, ˈrespɪreɪtə $ -ər/ BrE AmE noun [countable]
1 . a piece of equipment that pumps air in and out of someone’s lungs if they are too ill or weak to breathe SYN ventilator :
The baby was immediately put on a respirator.
2 . a piece of equipment that you wear over your nose and mouth to help you breathe in a place where there is harmful gas, smoke etc ⇨ gas mask