[spleen] n [ME splen, fr. MF or L; MF esplen, fr. L splen, fr. Gk splen; akin to L lien spleen, Skt plihan] (14c) 1: a highly vascular ductless organ that is located in the left abdominal region near the stomach or intestine of most vertebrates and is concerned with final destruction of red blood cells, filtration and storage of blood, and production of lymphocytes
2. obs: the seat of emotions or passions 3 archaic: melancholy
4: feelings of anger or ill will often suppressed
5. obs: a sudden impulse or whim: caprice syn see malice