The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. (Baseball, Cricket, Tennis, etc.) Done (as pitching or
      bowling) with the hand higher than the elbow, or the arm
      above, or higher than, the shoulder; as, an overhand
      pitch; an overhand stroke.
      [1913 Webster +PJC]

   Overhand knot. See Illustration of Knot.
      [1913 Webster]

WordNet (r) 3.0 (2006):

overhand knot
    n 1: a simple small knot (often used as part of other knots)