idle

Etymology 1

From Middle English idel, ydel, from Old English īdel, from Proto-West Germanic *īdal, from Proto-Germanic *īdalaz. Cognate with Dutch ijdel (“vain, meaningless”), German Low German iedel (“vain, idle”), German eitel (“vain, conceited”), and possibly Old Norse illr ("bad"; > English ill).

adj

1. (obsolete) Empty, vacant.
2. Not being used appropriately; not occupied; (of time) with no, no important, or not much activity.
   idle hours
   My computer hibernates after it has been idle for 30 minutes.
   The majority of accounts require no minimum balance and charge no monthly service fee. Where monthly fees and balance requirements exist, they're low. You earn no interest on the idle money in the account. 2009, Jane Bryant Quinn, Making the Most of Your Money Now
3. Not engaged in any occupation or employment; unemployed; inactive; doing nothing in particular.
   idle workmen
4. Averse to work, labor or employment; lazy; slothful.
   an idle fellow
5. Of no importance; useless; worthless; vain; trifling; thoughtless; silly.
   an idle story;  idle talk;  idle rumor
6. (obsolete) Light-headed; foolish.
   The youth is idle 1628, John Ford, The Lover's Melancholy

Etymology 2

From Middle English idelen, from Old English īdlian, from Proto-West Germanic *īdalēn. Cognate with German eiteln (“to make empty, free up”).

verb

1. (transitive) To spend in idleness; to waste; to consume.
2. (intransitive) To lose or spend time doing nothing, or without being employed in business.
   to idle in an IRC channel
   He had already heard of the young man's projected journey — evidently the Comte de Combourg had written many letters while his son idled at St. Malo […] 1939, Joan Evans, Chateaubriand, page 32
3. (intransitive) Of an engine: to run at a slow speed, or out of gear; to tick over.
   High levels of all pollutants were found during time idling in stations. October 6 2021, Paul Clifton, “Network News: RSSB research exposes poor air quality on diesel trains”, in RAIL, number 941, page 14

Etymology 3

From Middle English idel, ydel, from Old English īdel (“idleness”), from the adjective (see above).

noun

1. The state of idling, of being idle.
2. (mechanical engineering) The lowest selectable thrust or power setting of an engine.
3. (gaming) An idle animation.
4. (gaming) An idle game.