Conquer or master (8)
I believe the answer is:
surmount
I believe this clue is a double definition.
'conquer' is the first definition.
(thesaurus)
'master' is the second definition.
(I know that master can be written as surmount)
(Other definitions for surmount that I've seen before include "Overcome (obstacle)" , "Conquer, get the better of" , "Prevail over" , "Get on top of" , "Tight embrace" .)