An organ or a part, especially a tooth, having three cusps (points).

1. Having three cusps or points: Dr. Kilfoil examined the tricuspid teeth or molars in Janet's lower jaw and he noted that there were no new cavities.
2. Referring to a valve in the heart consisting of three membranous flaps at the opening of the right auricle and into the right ventricle as in the heart of most mammals: The cardiologist, Dr. Timmons, listened carefully to Sandra's heart so he could hear the action of the tricuspid valves in order to determine if there were any tricuspid obstructions.