The Collaborative International Dictionary of English v.0.48:

Tenace \Ten"ace\ (t[e^]n"[asl]s), n. [F. tenace tenacious,
   demeurer tenace to hold the best and third best cards and
   take both tricks, the adversary having to lead. See
   Tenacious.] (Whist)
   The holding by the fourth hand of the best and third best
   cards of a suit led; also, sometimes, the combination of best
   with third best card of a suit in any hand.
   [1913 Webster]