human being vs mortal

human being

noun
  • A person; a large sapient, bipedal primate, with notably less hair than others of that order, of the species Homo sapiens. 

  • Any member of the genus Homo, including extinct species. 

mortal

noun
  • A human; someone susceptible to death. 

adj
  • Human; belonging or pertaining to people who are mortal. 

  • Of or relating to the time of death. 

  • Punishable by death. 

  • Affecting as if with power to kill; deathly. 

  • Very painful or tedious; wearisome. 

  • Susceptible to death by aging, sickness, injury, or wound; not immortal. 

  • Causing death; deadly, fatal, killing, lethal (now only of wounds, injuries etc.). 

  • Of a sin: involving the penalty of spiritual death, rather than merely venial. 

  • Very drunk. 

  • Fatally vulnerable. 

adv
  • Mortally; enough to cause death. 

How often have the words human being and mortal occurred in a corpus of books? (source: Google Ngram Viewer )