Cage is put in for toucan at last (6)
I believe the answer is:
prison
'cage' is the definition.
(I've seen this in another clue)
'is put in for toucan at last' is the wordplay.
'put in' is an insertion indicator.
'for' becomes 'pro' (as in being 'pro' something).
'at last' says to take the final letters.
The last letter of 'toucan' is 'n'.
'is' put into 'pro' is 'priso'.
'priso'+'n'='PRISON'
(Other definitions for prison that I've seen before include "Correctional institution" , "Place of incarceration" , "Eg, Wormwood Scrubs" , "Place of confinement" , "cage" .)