Wimp gets the most out of work (7)
I believe the answer is:
milksop
'wimp' is the definition.
(I've seen this before)
'gets the most out of work' is the wordplay.
'gets the most out of' becomes 'milks' (milk can mean to exploit as much as possible).
'work' becomes 'op' (common abbreviation for 'opus').
'milks'+'op'='MILKSOP'
(Other definitions for milksop that I've seen before include "Weak or effeminate man" , "Weak type" , "Doormat" , "Weed" , "Chinless wonder" .)