Somehow trap a rich male head of family (9)
I believe the answer is:
patriarch
'male head of family' is the definition.
(I've seen this before)
'somehow trap a rich' is the wordplay.
'somehow' indicates anagramming the letters.
'trap'+'a'+'rich'='traparich'
'traparich' anagrammed gives 'PATRIARCH'.
(Other definitions for patriarch that I've seen before include "Male head of family or tribe" , "Paterfamilias" , "like Abraham was" , "Father figure" , "tribal head" .)