Sentence:  Such understanding helps to explain why one matron celebrating thirty-five years of married life could declare with some pride that her husband had `` never seen her entirely naked '' , while another woman , boasting an equal number of years of married life , <WSD>is</WSD> proud of having `` shared the nudist way of life - the really free , natural nude life - for most of that period '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)