Source : Webster's Revised Unabridged Dictionary (1913)

Depopulate \De*pop"u*late\, v. t. [imp. & p. p. {Depopulated};
   p. pr. & vb. n. {Depopulating}.] [L. depopulatus, p. p. of
   depopulari to ravage; de- + populari to ravage, fr. populus
   people: cf. OF. depopuler, F. d['e]peupler. See {People}.]
   To deprive of inhabitants, whether by death or by expulsion;
   to reduce greatly the populousness of; to dispeople; to
   unpeople.

         Where is this viper, That would depopulate the city?
                                                  --Shak.

   Note: It is not synonymous with laying waste or destroying,
         being limited to the loss of inhabitants; as, an army
         or a famine may depopulate a country. It rarely
         expresses an entire loss of inhabitants, but often a
         great diminution of their numbers; as, the deluge
         depopulated the earth.

Depopulate \De*pop"u*late\, v. i.
   To become dispeopled. [R.]

         Whether the country be depopulating or not.
                                                  --Goldsmith.

Source : WordNet®

depopulate
     v : reduce in population; "The epidemic depopulated the
         countryside" [syn: {desolate}]