Definition of "Idle" :

noun: the state of an engine or other mechanism that is idling

"The car engine was running at idle."

verb: run disconnected or idle

verb: be idle; exist in a changeless situation

adjective: not in active use

"The machinery sat idle during the strike."

adjective: not in action or at work

"An idle laborer."

adjective: not having a job

"Idle carpenters."

adjective: not yielding a return

"Idle funds."

adjective: lacking a sense of restraint or responsibility

"Idle talk."

adjective: silly or trivial

"Idle pleasure."

adjective: without a basis in reason or fact

"Idle fears."