Source : Webster's Revised Unabridged Dictionary (1913)

Extrinsic \Ex*trin"sic\, a. [L. extrinsecus; exter on the
   outside + secus otherwise, beside; akin to E. second: cf. F.
   extrins[`e]que. See {Exterior}, {Second}.]
   1. Not contained in or belonging to a body; external;
      outward; unessential; -- opposed to intrinsic.

            The extrinsic aids of education and of artificial
            culture.                              --I. Taylor.

   2. (Anat.) Attached partly to an organ or limb and partly to
      some other part? -- said of certain groups of muscles.
      Opposed to intrinsic.

Source : WordNet®

extrinsic
     adj : not forming an essential part of a thing or arising or
           originating from the outside; "extrinsic evidence"; "an
           extrinsic feature of the new building"; "that style is
           something extrinsic to the subject"; "looking for
           extrinsic aid" [ant: {intrinsic}]