mor‧tal‧i‧ty plural mortalities
1 [uncountable] also mortality rateSSMX
the number of deaths during a particular period of time among a particular type or group of people:
Mortality from heart disease varies widely across the world.
the condition of being human and having to die [≠ immortality]:
My mother's death forced me to face the fact of my own mortality.
3 [countable] technical
mortalities from cancer