ENGINE[I]›If an engine or machine idles, it runs slowly but does not move or do any work: He left the engine idling and ran into the shop.
STOP WORKING[T]US›to stop someone or something working or being used, often because there is not enough work to do: The closure of the plant idled about 300 workers.
TIME[I]›to spend time doing nothing: We saw her idling in the school grounds.