Alphonso, perhaps he is game (5)
I believe the answer is:
mango
'alphonso perhaps he is game' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'he is game' is the wordplay.
'he' becomes 'man' ().
'is game' becomes 'go'.
'man'+'go'='MANGO'
Can you help me to learn more?
(Other definitions for mango that I've seen before include "No, Mag has the odd fruit" , "Once exotic fruit" , "Tropical fruit, its pickle" , "fruit-tree" , "product" .)