Source : Webster's Revised Unabridged Dictionary (1913)

Extermination \Ex*ter`mi*na"tion\, n. [Cf. F. extermination.]
   1. The act of exterminating; total destruction; eradication;
      excision; as, the extermination of inhabitants or tribes,
      of error or vice, or of weeds from a field.

   2. (Math.) Elimination. [R.]

Source : WordNet®

extermination
     n 1: complete annihilation; "they think a meteor cause the
          extinction of the dinosaurs" [syn: {extinction}]
     2: the act of exterminating [syn: {liquidation}]