Sentence:  `` The white colonnaded , cedar-roofed Southern mansion <WSD>is</WSD> directly traceable via the gray and buff stone of grey-skied England to the golden stucco of one particular part of the blue South , the Palladian orbit stretching out from Vicenza : the old mind of Andrea Palladio still smiles from behind many an old rocking chair on a Southern porch , the deep friezes of his architectonic music rise firm above the shallower freeze in the kitchen , his feeling for light and shade brings a glitter from a tall mint julep , his sense of columns framing the warm velvet night has brought together a million couple of mating lips '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)