Others sleep (4)
I believe the answer is:
rest
I believe this clue is a double definition.
'others' is the first definition.
(eg the rest of a group)
'sleep' is the second definition.
(I know that sleep can be written as rest)
(Other definitions for rest that I've seen before include "Motionlessness" , "Others; relax" , "Remain" , "Take a breather - (the) others" , "Lie down" .)