Kills time (5)
I believe the answer is:
idles
'kills time' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for idles that I've seen before include "Spends time doing nothing" , "Lazes around" , "Does little, just ticks over" , "Of engine, just ticks over in neutral" , "Wastes time" .)