Out of order, so he put a sock in it! (4)
I believe the answer is:
shoe
'put a sock in it' is the definition.
(shoes are worn over socks)
'out of order so he' is the wordplay.
'so he' can be anagrammed to 'SHOE'.
However, I am not sure how this is indicated.
(Other definitions for shoe that I've seen before include "Trainer perhaps" , "Brogue, for example" , "Plate nailed to underside of horse's hoof" , "Case for cards in a casino" , "Playing card box" .)