Menacing husband on far side of river, energy-charged (8)
I believe the answer is:
tigerish
'menacing' is the definition.
'husband on far side of river energy-charged' is the wordplay.
'husband' becomes 'h'.
'on far side of' means one lot of letters go next to another.
'river' becomes 'tigris' (Tigris River is an example**).
'energy' becomes 'e' (physics symbol as in E=mci).
'charged' means one lot of letters goes inside another (charged can mean filled with).
'tigris' placed around 'e' is 'tigeris'.
'h' put after 'tigeris' is 'TIGERISH'.
(Other definitions for tigerish that I've seen before include "Fierce" , "feistiness" .)