Idle  —adj. (idler, idlest) 1 lazy, indolent. 2 not in use; not working. 3 (of time etc.) Unoccupied. 4 purposeless; groundless (idle rumour). 5 useless, ineffective (idle protest). —v. (-ling) 1 be idle. 2 run (an engine) or (of an engine) be run slowly without doing any work. 3 (foll. By away) pass (time etc.) In idleness.  idleness n. Idler n. Idly adv. [old english]