48. The preceeding film shows the pulmonary plethora of ASD pleth·o·ra [ pleth -er- uh ] –noun 1.overabundance; excess: a plethora of advice and a paucity of assistance. 2. Pathology Archaic . a morbid condition due to excess of red corpuscles in the blood or increase in the quantity of blood. [Origin: 1535–45; < NL < Gk pléthra fullness]