Sentence:  He knew just the thing for her - a treatment from his `` cosmic light <WSD>ozone</WSD> generator '' machine . 
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)