Malcontent with love for Marx? (7)
I believe the answer is:
groucho
'marx?' is the definition.
(comedian Groucho Marx)
'malcontent with love' is the wordplay.
'malcontent' becomes 'grouch' (both can mean a dissatisfied person).
'with' is a charade indicator (letters next to each other).
'love' becomes 'o' (In tennis, 'love' means 'zero').
'grouch'+'o'='GROUCHO'
'for' acts as a link.
(Other definitions for groucho that I've seen before include "One of Harpo's brothers" , "A Marx; a club" , "Funny man" , "One of Marx Brothers" , "One of four comedian brothers" .)