Slid off tops (4)
I believe the answer is:
lids
'tops' is the definition.
(I know this)
'slid off' is the wordplay.
'off' indicates an anagram.
'slid' anagrammed gives 'LIDS'.
(Other definitions for lids that I've seen before include "Movable tops or covers" , "Covers for opening and closing" , "Eye covers" .)