Nicolas of "Con Air" (4)
I believe the answer is:
cage
'nicolas of con air' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cage that I've seen before include "Imprison, confine" , "Hutch" , "Enclosure of wire or metal bars" , "US composer -- barred enclosure" , "Put behind bars" .)