Golf side’s sad, wretched existence (4,4)
I believe the answer is:
dogs life
'wretched existence' is the definition.
'golf side's sad' is the wordplay.
'sad' indicates an anagram.
'golf'+'side'='golfside'
'golfside' is an anagram of 'DOGS LIFE'.
(Other definitions for dogs life that I've seen before include "Miserable existence of canine origin" , "A really rotten existence of canine origin" , "A miserable existence of canine analogy (3'1,4)" , "hard time" , "Miserable existence of canine hue (3'1,4)" .)