Source : Webster's Revised Unabridged Dictionary (1913)

Morbidity \Mor*bid"i*ty\, n.
   1. The quality or state of being morbid.

   2. Morbid quality; disease; sickness. --C. Kingsley.

   3. Amount of disease; sick rate.

Source : WordNet®

morbidity
     n 1: the ratio of deaths in an area to the population of that
          area; expressed per 1000 per year [syn: {deathrate}, {death
          rate}, {mortality}, {mortality rate}, {fatality rate}]
     2: the relative incidence of a particular disease
     3: the quality of being unhealthful and generally bad for you
        [syn: {unwholesomeness}, {morbidness}] [ant: {wholesomeness}]