Source : Webster's Revised Unabridged Dictionary (1913)

Extensive \Ex*ten"sive\, a. [L. extensivus: cf. F. extensif. See
   {Extend}.]
   1. Having wide extent; of much superficial extent; expanded;
      large; broad; wide; comprehensive; as, an extensive farm;
      an extensive lake; an extensive sphere of operations;
      extensive benevolence; extensive greatness.

   2. Capable of being extended. [Obs.]

            Silver beaters choose the finest coin, as that which
            is most extensive under the hammer.   --Boyle.

Source : WordNet®

extensive
     adj 1: large in spatial extent or range; "an extensive Roman
            settlement in northwest England"; "extended farm
            lands" [syn: {extended}]
     2: having broad range or effect; "had extensive press
        coverage"; "far-reaching changes in the social structure";
        "sweeping reforms" [syn: {far-reaching}, {sweeping}]
     3: large in number or quantity (especially of discourse); "she
        took copious notes"; "extensive press coverage"; "a
        subject of voluminous legislation" [syn: {copious}, {voluminous}]
     4: great in range or scope; "an extended vocabulary"; "surgeons
        with extended experience"; "extensive examples of picture
        writing"; "suffered extensive damage"; "a wide selection"
        [syn: {extended}, {wide}]
     5: of agriculture; increasing productivity by using large areas
        with minimal outlay and labor; "producing wheat under
        extensive conditions"; "agriculture of the extensive type"
        [ant: {intensive}]