Imo. Your always doing something, your using your time and not killing it, worthlessly throwing it away. I guess you could say if you were a lazy ass person who did nothing then maybe when you stare at a blank wall its killing time. To me, everyone is still using there time. I mean its either -use your time wisely- -Kiling time- .
I have a time plant growing at my house that i poison daily... early in the morning... when i wake up... But anyways, i think thats spelt "thyme"...
time is semi-ilusion spanding across space and matter itself. Unlike what most people think time is not like a river, its actualy more like a big ball of wibbly wobbly time strings that we could hop onto once we get high enough from a tech view. So no, time cant be killed.