Fruit: bloke gets one out (10)
I believe the answer is:
'fruit' is the definition.
(I know that mangosteen is a fruit)
'bloke gets one out' is the wordplay.
'bloke' becomes 'man' (informal term for a man).
'out' indicates an anagram (out can mean wrong or inaccurate).
'getsone' is an anagram of 'gosteen'.
(Another definition for mangosteen that I've seen is " Tropical fruit".)