Source : Webster's Revised Unabridged Dictionary (1913)

Left-handed \Left"-hand`ed\, a.
   1. Having the left hand or arm stronger and more dexterous
      than the right; using the left hand and arm with more
      dexterity than the right.

   2. Clumsy; awkward; unlucky; insincere; sinister; malicious;
      as, a left-handed compliment.

            The commendations of this people are not always
            left-handed and detractive.           --Landor.

   3. Having a direction contrary to that of the hands of a
      watch when seen in front; -- said of a twist, a rotary
      motion, etc., looked at from a given direction.

   {Left-handed marriage}, a morganatic marriage. See
      {Morganatic}.

   {Left-handed screw}, a screw constructed to advance away from
      the observer, when turned, as in a nut, with a left-handed
      rotation. An ordinary wood screw is right-handed.

Source : WordNet®

left-handed
     adj 1: using or intended for the lefts hand; "left-handed golfers
            need left-handed clubs"; "left-handed scissors" [ant:
            {ambidextrous}, {right-handed}]
     2: (of marriages) illicit or informal; "in Colonial America
        left-handed marriages between Frenchmen and Indians were
        frequent"
     3: (of marriages) of a marriage between one of royal or noble
        birth and one of lower rank; valid but with the
        understanding that the rank of the inferior remains
        unchanged and offspring do not succeed to titles or
        property of the superior [syn: {morganatic}]
     4: rotating to the left [syn: {levorotary}, {levorotatory}]
     5: ironically ambiguous; "a left-handed compliment"
     6: not skillful in physical movement especially with the hands;
        "a bumbling mechanic"; "a bungling performance";
        "ham-handed governmental interference"; "could scarcely
        empty a scuttle of ashes, so handless was the poor
        creature"- Mary H. Vorse [syn: {bumbling}, {bungling}, {butterfingered},
         {ham-fisted}, {ham-handed}, {handless}, {heavy-handed}]