GC: n

S: http://www.nlm.nih.gov/medlineplus/spleendiseases.html (last access: 29 July 2015); DORLAND p. 1751.

N: 1. c.1300, from Old French esplen, from Latin splen, from Greek splen “the milt, spleen,” from PIE *spelgh- “spleen, milt” (cognates: Sanskrit plihan-, Avestan sperezan, Armenian p’aicaln, Latin lien, Old Church Slavonic slezena, Lithuanian blužnis, Old Prussian blusne, Old Irish selg “spleen”).
Regarded in medieval physiology as the seat of morose feelings and bad temper. Hence figurative sense of “violent ill-temper” (1580s, implied in spleenful); and thence spleenless “free from anger, ill-humor, malice, or spite” (1610s).
2. Organ of the lymphatic system located in the left side of the abdominal cavity under the diaphragm, the muscular partition between the abdomen and the chest. In humans it is about the size of a fist and is well supplied with blood. As the lymph nodes are filters for the lymphatic circulation, the spleen is the primary filtering element for the blood. The organ also plays an important role in storing and releasing certain types of immune cells that mediate tissue inflammation.
3. Cultural Interrelation: We can mention Paris Spleen (1869, in French) by Charles Baudelaire (1821-1867).

S: 1. OED – http://www.etymonline.com/index.php?term=spleen (last access: 29 July 2014). 2. EncBrit – http://global.britannica.com/science/spleen-anatomy (last access: 5 April 2015). 3. http://www.almaclassics.com/excerpts/Paris_Spleen.pdf (last access: 5 April 2015).

SYN:
S:

CR: hypochondria, hypochondriac.