Sentence:  His next major work , completed in 1892 , <WSD>was</WSD> a long fantastic epic in prose , entitled Hans Alienus , which Professor Bo ^ o ^ k describes as a monument on the grave of his carefree and indolent youth . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)