Put bananas in unusual transport (7)
I believe the answer is:
rapture
'transport' is the definition.
('rapture' can be a synonym of 'transport')
'put bananas in unusual' is the wordplay.
'bananas' indicates an anagram (informal term for mad).
'in' is an insertion indicator.
'unusual' becomes 'rare' (I've seen this before).
'put' with letters rearranged gives 'ptu'.
'ptu' going within 'rare' is 'RAPTURE'.
(Other definitions for rapture that I've seen before include "Transports of delight" , "Exaltation" , "transport" , "State of bliss and euphoria" , "modified for Nanki-Poo?" .)