Just sitting around (4)
I believe the answer is:
idle
'just sitting around' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for idle that I've seen before include "Dormant" , "'Lazy, not doing anything (4)'" , "Unoccupied or not in use" , "not being engaged" , "Run out of gear" .)