My boss improved it originally? Only partly (6)
I believe the answer is:
editor
'my boss' is the definition.
(the crossword setter's boss is a newspaper editor)
'improved it originally? only partly' is the wordplay.
'only partly' says the answer is hidden in the clue.
'EDITOR' is hidden within 'improved it originally'.
(Other definitions for editor that I've seen before include "Script-preparer" , "Press chief" , "Press fellow" , "One prepares a work for publication" , "Rag worker" .)