WordNet

not in action or at work; "an idle laborer"; "idle drifters"; "the idle rich"; "an idle mind"
the state of an engine or other mechanism that is idling; "the car engine was running at idle"
not having a job; "idle carpenters"; "jobless transients"; "many people in the area were out of work" (同)jobless, out of work
be idle; exist in a changeless situation; "The old man sat and stagnated on his porch"; "He slugged in bed all morning" (同)laze, slug, stagnate
silly or trivial; "idle pleasure"; "light banter"; "light idle chatter" (同)light
lacking a sense of restraint or responsibility; "idle talk"; "a loose tongue" (同)loose
run disconnected or idle; "the engine is idling" (同)tick over
not in active use; "the machinery sat idle during the strike"; "idle hands" (同)unused

PrepTutorEJDIC

(人が)『働いていない』(unemployed),(機械などが)使われていない,(時間が)空いている / (人が)『怠惰な』,怠けている / 価値のない,むだな / 〈人が〉何もしないでいる,ぶらぶらと時間を過ごす《+『about』》 / 〈機械などが〉から回りし続ける,アイドリングする / 〈時間〉‘を'空費する,ぶらぶらして過ごす《+『名』+『away』,+『away』+『名』》 / 〈不景気・ストライキなどが〉〈人・機械など〉‘を'遊ばせる,暇にさせる