Sentence:  Eager as he <WSD>was</WSD> to pursue this promising line , he was so loaded down with the management of the pharmacy and lectures in the medical and pharmaceutical faculties at the university that he could devote only Sunday afternoons to `` galvanizing '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)