Sentence:  ... she kept toying with a pair of old sunglasses which lay beside her on the kitchen table. One of the <WSD>bows</WSD> had been mended with adhesive tape, and one of the lenses was cracked. 
Meaning of the word marked with <WSD> tags:  Either of the arms of a pair of spectacles, running from the side of the lens to behind the wearer's ear.