Be typical of male if in trade south of river (9)
I believe the answer is:
exemplify
'be typical of' is the definition.
'male if in trade south of river' is the wordplay.
'male' becomes 'm' (common abbreviation).
'in' means one lot of letters goes inside another.
'trade' becomes 'ply'.
'south of' is a charade indicator (letters next to each other).
'river' becomes 'exe' (I've seen this before**).
'if' put within 'ply' is 'plify'.
'm'+'plify'='mplify'
'mplify' put after 'exe' is 'EXEMPLIFY'.
(Other definitions for exemplify that I've seen before include "Give an illustration of" , "Illustrate" .)