spleen
n. countablen. an organ in your body that helps clean your blood and fight infections. In older books, it also means a feeling of anger or bad temper.
n. a vascular organ located in the upper left abdomen that filters blood and plays a role in the immune system. In a literary or historical context, it refers to a state of irritable anger or melancholy.
The doctor checked his spleen for any signs of swelling.
After the accident, the surgeon had to perform an emergency operation to repair the patient's ruptured spleen.
The critic used his weekly column to vent his spleen against the modern art movement, attacking every new exhibition with a mixture of wit and genuine vitriol.
From Middle English splene, splen, from Anglo-Norman espleen and Old French esplein, esplen, from Latin splēn (“milt”), from Ancient Greek σπλήν (splḗn, “the spleen”). Doublet of lien. Partially displaced the native English term milt.
The anatomical sense is countable; the figurative sense meaning 'anger' is uncountable and often appears in the phrase 'vent one's spleen'.