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 <WSD>die</WSD> tomorrow , still I have had twenty-eight wonderful years ; but I sha n't die tomorrow ; I 'll live to be 105 '' . 
Meaning of the word marked with <WSD> tags:  pass from physical life and lose all bodily attributes and functions necessary to sustain life