Sentence:  Yes , the <WSD>ozone</WSD> from his machine would cure practically everything , he assured her . 
Meaning of the word marked with <WSD> tags:  a colorless gas (O3) soluble in alkalis and cold water; a strong oxidizing agent; can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)