noun

1. a large, vascular, lymphatic organ in the upper left part of the abdominal cavity of vertebrates, near the stomach: it has various functions in modifying the structure of the blood, and was formerly regarded as the seat of certain emotions
2. 1. malice; spite; bad temper
   2. Archaic melancholy; low spirits
   3. Obsolete a whim or caprice

Etymology: ME splen < OFr esplen < L splen < Gr splēn, spleen < IE *sp(h)elĝh- > Sans plīhan, OSlav slězena, spleen