Store where hens sleep (4)

I believe the answer is:

coop

I'm a little stuck... Click here to teach me more about this clue!

'store' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

(Other definitions for coop that I've seen before include "Cage for poultry" , "Birdcage" , "Pen" , "Hens in this" , "pound" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app