Sentence:  A Clerfayt may moon on about the face of Death in the cockpit ; a Portago could say , as he did say to me , `` If I die tomorrow , still I have had twenty-eight wonderful years ; but I sha n't die tomorrow ; I 'll live to <WSD>be</WSD> 105 '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)