Organ near the stomach (6)
I believe the answer is:
spleen
'organ near the stomach' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for spleen that I've seen before include "Body organ or bad temper" , "Bodily organ associated with bad humour" , "Quick temper -- spite" , "Bad temper from stomach organ" , "Organ supposedly controlling temper" .)