res‧pi‧ra‧tor /ˈrespəreɪtə, ˈrespɪreɪtə $ -ər/ 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 Synonym : 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

[TahlilGaran] Dictionary of Contemporary English ▲