Relating to the liver (7)
I believe the answer is:
hepatic
'relating to the liver' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for hepatic that I've seen before include "of an organ" , "brownish-red" , "Livery" , "Pertaining to, or affecting, the liver or liverwort" , "Relating to the liver" .)