Father, having retired, has little desire for food (8)
I believe the answer is:
appetite
'desire for food' is the definition.
(I've seen this before)
'father having retired has little' is the wordplay.
'father' becomes 'pa' (pa can mean dad or father).
'having retired' says the letters should be written in reverse.
'has' is a charade indicator (letters next to each other).
'little' becomes 'petite' (similar in meaning).
'pa' back-to-front is 'ap'.
'ap'+'petite'='APPETITE'
(Other definitions for appetite that I've seen before include "demand" , "Physical desire as for food" , "Natural desire to satisfy a need" , "thirst" , "Keenness for food" .)