The Collaborative International Dictionary of English v.0.48:

standoff \stand"off\ a.
   Serving to keep two objects or parts of a machine separated;
   as, a standoff insulator.
   [PJC] standoffish

The Collaborative International Dictionary of English v.0.48:

standoff \stand"off\ n.
   1. A situation in a contest in which the winner is undecided;
      a draw or stalemate.

   Syn: draw; tie; stalemate; deadlock
        [WordNet 1.5]

   2. A successful stand.

   Syn: repulsion, repelling
        [WordNet 1.5]

   3. Something that serves to keep one object at a distance
      from another, such as a prop attached to the top of a
      ladder to keep it from leaning directly against the
      vertical surface which suports it.
      [PJC]

WordNet (r) 3.0 (2006):

standoff
    n 1: the finish of a contest in which the score is tied and the
         winner is undecided; "the game ended in a draw"; "their
         record was 3 wins, 6 losses and a tie" [syn: draw,
         standoff, tie]
    2: the act of repulsing or repelling an attack; a successful
       defensive stand [syn: repulsion, standoff]