Sentence:  He thought how this dainty , fragile older woman threading her way through the streets of Westminster on a day in June , enjoying the flowers in the shops , the greetings from old friends , but never really drawing a deep , passionate breath , <WSD>was</WSD> so like himself . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)