The Collaborative International Dictionary of English v.0.48:

Terminal \Ter"mi*nal\ (-nal), a. [L. terminals: cf. F. terminal.
   See Term, n.]
   1. Of or pertaining to the end or extremity; forming the
      extremity; as, a terminal edge.
      [1913 Webster]

   2. (Bot.) Growing at the end of a branch or stem;
      terminating; as, a terminal bud, flower, or spike.
      [1913 Webster]

   3. (Railroads) Pertaining to a railroad terminal; connected
      with the receipt or delivery of freight; as, terminal
      charges.
      [Webster 1913 Suppl.]

   Terminal moraine. See the Note under Moraine.

   Terminal statue. See Terminus, n., 2 and 3.

   Terminal velocity.
      (a) The velocity acquired at the end of a body's motion.
      (b) The limit toward which the velocity of a body
          approaches, as of a body falling through the air.
          [1913 Webster]

WordNet (r) 3.0 (2006):

terminal velocity
    n 1: the constant maximum velocity reached by a body falling
         through the atmosphere under the attraction of gravity