Work with love and endless thrust (4)
I believe the answer is:
opus
'work' is the definition.
(an opus is an artistic work)
'love and endless thrust' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'and' says to put letters next to each other.
'endless' means to remove the last letter.
'thrust' becomes 'push' (synonyms).
'push' with its last letter taken away is 'pus'.
'o'+'pus'='OPUS'
'with' acts as a link.
(Other definitions for opus that I've seen before include "Piece of music (with number)" , "Work or composition, usually musical" , "Soup (anag.)" , "Artistic work" , "Showing creative skill" .)