Source : Webster's Revised Unabridged Dictionary (1913)

Overhand \O"ver*hand`\, n.
   The upper hand; advantage; superiority; mastery.

         He had gotten thereby a great overhand on me. --Sir T.
                                                  More.

Overhand \O"ver*hand`\, a.
   1. (Sewing) Over and over; -- applied to a style of sewing,
      or to a seam, in which two edges, usually selvedges, are
      sewed together by passing each stitch over both.

   2. (Baseball, Cricket, etc.) Done (as pitching or bowling)
      with the hand higher than the elbow, or the arm above, or
      higher than, the shoulder.

   {Overhand knot}. See Illustration of {Knot}.

Overhand \O"ver*hand`\, adv.
   In an overhand manner or style.

Source : WordNet®

overhand
     adj 1: with hand brought forward and down from above shoulder
            level; "an overhand pitch"; "an overhand stroke" [syn:
             {overhanded}, {overarm}] [ant: {underhand}]
     2: sewn together with overhand stitches (close vertical
        stitches that pass over and draw the two edges together)
        [syn: {oversewn}]