Sentence:  Daughter of a gypsy mother who taught her to dance , she <WSD>is</WSD> one of the few really beautiful girls in the New York casbah , with dark eyes and dark , waist-length hair , the face of an adolescent patrician and a lithe , glimmering body . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)