Source : Webster's Revised Unabridged Dictionary (1913)

Tricuspid \Tri*cus"pid\, a. [L. tricuspis, -idis; tri- (see
   {Tri-}) + cuspis a point: cf. F. tricuspide.]
   1. Having three cusps, or points; tricuspidate; as, a
      tricuspid molar.

   2. (Anat.) Of or pertaining to the tricuspid valves; as,
      tricuspid obstruction.

   {Tricuspid valve} (Anat.), the valve, consisting of three
      triangular membranous flaps, at the opening of the right
      auricle into the right ventricle in the heart of most
      mammals; -- sometimes called the {tricuspid valves}, each
      flap being regarded as a valve.

Source : WordNet®

tricuspid valve
     n : valve with three cusps; situated between the right atrium
         and the right ventricle; allows blood to pass from atrium
         to ventricle and closes to prevent backflow when the
         ventricle contracts [syn: {right atrioventricular valve}]