Fellow with good old fruit (5)
I believe the answer is:
mango
'fruit' is the definition.
(type of fruit)
'fellow with good old' is the wordplay.
'fellow' becomes 'man' (fellow can mean a man).
'with' is a charade indicator (letters next to each other).
'good' becomes 'g' (abbreviation).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'man'+'g'+'o'='MANGO'
(Other definitions for mango that I've seen before include "fruit tree" , "Fleshy tropical fruit" , "Asian fruit" , "fruit-tree" , "Large oval tropical fruit" .)