Be like Norman William, sounding like a nut (7)
I believe the answer is:
conquer
'be like norman william sounding like a nut' is the definition.
I can't judge whether this definition defines the answer.
'sounding like a nut' is the wordplay.
'sounding like' shows a homophone (sound like).
'a nut' becomes 'conker' (the nut of a horse chestnut tree).
'conker' sounds like 'CONQUER'.
Can you help me to learn more?
(Other definitions for conquer that I've seen before include "to follow William's example" , "Put down by force" , "Overcome militarily" , "Act like William" , "Crush" .)