Sentence:  She watched him walk to the bed set on its foot-high dais, watched him walk in his bare feet, big feet that were really quite beautiful, watched him pull the covers back, <WSD>unsash</WSD> the dressing gown, shrug it off, and naked as a black-haired god, climb into the bed. 
Meaning of the word marked with <WSD> tags:  To untie the sash that holds an article of clothing.