Enclosure with bars (4)
I believe the answer is:
cage
'enclosure with bars' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for cage that I've seen before include "US composer -- barred enclosure" , "Confine behind bars" , "Nicolas - - (films)" , "Prison (with bars)" , "Tffhe goal in ice hockey" .)