What does "tricuspid" mean?

Tricuspid: (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.