Draining liquid food served with fish (9)
I believe the answer is:
gruelling
'draining liquid' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
'food served with fish' is the wordplay.
'food' becomes 'gruel' (gruel is a kind of food).
'served with' means one lot of letters go next to another.
'fish' becomes 'ling' (ling is a kind of fish).
'gruel'+'ling'='GRUELLING'
Can you help me to learn more?
(Other definitions for gruelling that I've seen before include "Severe" , "Strenuous" , "Arduous, backbreaking" , "Demanding" .)