Enclosures for writers (4)
I believe the answer is:
pens
This clue is a double definition.
'enclosures' is the first definition.
(pen is a kind of enclosure)
'for writers' is the second definition.
(writing implements)
(Other definitions for pens that I've seen before include "stalls" , "Livestock enclosures" , "Imprisons" , "Writing implements" , "Literary thought or reflection" .)