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 be...