Sentence:  Almost immediately she was ashamed of herself for feeling vain , at such a time , in such a place , and she tossed back her long yellow <WSD>hair</WSD> , smiling shyly as she entered the room . 
Meaning of the word marked with <WSD> tags:  a covering for the body (or parts of it) consisting of a dense growth of threadlike structures (as on the human head); helps to prevent heat loss