Webster's Revised Unabridged Dictionary · 1913

Idle

Idle , adjective

[Old English idel, Anglo-Saxon īdel vain, empty, useless; akin to Old Saxon īdal, Dutch ijdel, Old High German ītal vain, empty, mere, German eitel, Danish & Swedish idel mere, pure, and prob. to Greek {not transcribed} clear, pure, {not transcribed} to burn. Compare Ether.]

1.
Of no account; useless; vain; trifling; unprofitable; thoughtless; silly; barren.
Deserts idle. — Shakespeare
Every idle word that men shall speak, they shall give account thereof in the day of judgment. — Matt. xii. 36
Down their idle weapons dropped. — Milton
This idle story became important. — Macaulay
2.
Not called into active service; not turned to appropriate use; unemployed; as, idle hours.
The idle spear and shield were high uphing. — Milton
3.
Not employed; unoccupied with business; inactive; doing nothing; as, idle workmen.
Why stand ye here all the day idle? — Matt. xx. 6
4.
Given rest and ease; averse to labor or employment; lazy; slothful; as, an idle fellow.
5.
Light-headed; foolish. [Obsolete] — Ford
Collocations (3)
Idle pulley (Machinery) , a pulley that rests upon a belt to tighten it; a pulley that only guides a belt and is not used to transmit power.
Idle wheel (Machinery) , a gear wheel placed between two others, to transfer motion from one to the other without changing the direction of revolution.
In idle , in vain. [Obsolete] God saith, thou shalt not take the name of thy Lord God in idle. — Chaucer

Idle , intransitive verb

To lose or spend time in inaction, or without being employed in business. — Shakespeare

Idle , transitive verb

To spend in idleness; to waste; to consume; -- often followed by away; as, to idle away an hour a day.