Source : Webster's Revised Unabridged Dictionary (1913)

Mechanical \Me*chan"ic*al\, a. [From {Mechanic}, a.]
   1. Pertaining to, governed by, or in accordance with,
      mechanics, or the laws of motion; pertaining to the
      quantitative relations of force and matter, as
      distinguished from mental, vital, chemical, etc.; as,
      mechanical principles; a mechanical theory; mechanical
      deposits.

   2. Of or pertaining to a machine or to machinery or tools;
      made or formed by a machine or with tools; as, mechanical
      precision; mechanical products.

            We have also divers mechanical arts.  --Bacon.

   3. Done as if by a machine; uninfluenced by will or emotion;
      proceeding automatically, or by habit, without special
      intention or reflection; as, mechanical singing;
      mechanical verses; mechanical service.

   4. Made and operated by interaction of forces without a
      directing intelligence; as, a mechanical universe.

   5. Obtained by trial, by measurements, etc.; approximate;
      empirical. See the 2d Note under {Geometric}.

   {Mechanical effect}, effective power; useful work exerted, as
      by a machine, in a definite time.

   {Mechanical engineering}. See the Note under {Engineering}.
      

   {Mechanical maneuvers} (Mil.), the application of mechanical
      appliances to the mounting, dismounting, and moving of
      artillery. --Farrow.

   {Mechanical philosophy}, the principles of mechanics applied
      to the inverstigation of physical phenomena.

   {Mechanical powers}, certain simple instruments, such as the
      lever and its modifications (the wheel and axle and the
      pulley), the inclined plane with its modifications (the
      screw and the wedge), which convert a small force acting
      through a great space into a great force acting through a
      small space, or vice versa, and are used separately or in
      combination.

   {Mechanical solution} (Math.), a solution of a problem by any
      art or contrivance not strictly geometrical, as by means
      of the ruler and compasses, or other instruments.

Mechanical \Me*chan"ic*al\, n.
   A mechanic. [Obs.] --Shak.

Source : WordNet®

mechanical
     adj 1: using (or as if using) mechanisms or tools or devices; "a
            mechanical process"; "his smile was very mechanical";
            "a mechanical toy" [ant: {nonmechanical}]
     2: relating to or concerned with machinery or tools;
        "mechanical arts"; "mechanical design"; "mechanical
        skills" [syn: {mechanically skillful}]
     3: relating to or governed by or in accordance with mechanics;
        "a belief that the universe is a mechanical contrivance";
        "the mechanical pressure of a strong wind"
     4: lacking thought or feeling [syn: {mechanistic}]