"The West Wing" creator Sorkin (5)
I believe the answer is:
aaron
'the west wing creator sorkin' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for aaron that I've seen before include "Moses's brother" , "Bearded fellow" , "high priest" , "leader's brother" , "Brother of Moses, led the Jews to the Promised Land" .)