Good knight embracing maiden possibly in control (6)
I believe the answer is:
govern
'control' is the definition.
(to govern is to control or rule over)
'good knight embracing maiden possibly' is the wordplay.
'good' becomes 'g' (abbreviation).
'knight' becomes 'N' (chess abbreviation).
'embracing' is an insertion indicator.
'maiden possibly' becomes 'over' (maiden is a kind of over).
'g'+'n'='gn'
'gn' enclosing 'over' is 'GOVERN'.
'in' is the link.
(Other definitions for govern that I've seen before include "Control, influence" , "Control and direct the affairs of" , "Be in power" , "Rule with authority, perhaps a country" , "'Rule over, control (6)'" .)