Source : Webster's Revised Unabridged Dictionary (1913)

Demography \De*mog"ra*phy\, n. [Gr. ? the people + -graphy.]
   The study of races, as to births, marriages, mortality,
   health, etc. -- {Dem`o*graph"ic}, a.

Source : WordNet®

demography
     n : the branch of sociology that studies the characteristics of
         human populations [syn: {human ecology}]