Cages writers (4)
I believe the answer is:
pens
This clue is a double definition.
'cages' is the first definition.
(I've seen this in another clue)
'writers' is the second definition.
(writing implements)
(Other definitions for pens that I've seen before include "Livestock enclosures" , "Female swans" , "Literary thought or reflection" , "stalls" , "writers" .)