Synonyms for Idle:

adj.

all (adjective)
loose, dead, unused, light.
free (adjective)
unengaged.
groundless (adjective)
unwarranted, unsupported.
inactive (adjective)
fallow, still, inactive, unemployed, sleepy, lethargic, sedentary, dormant, Snail-paced, jobless, unmoving, stationary, unworking, supine, motionless, lifeless.
inert (adjective)
lethargic, comatose, catatonic, sedentary, passive, insensible, vegetative, inactive, lifeless, stationary, dormant, apathetic, immobile, sluggard, Reposing, inanimate, languorous, listless, languid, stagnant, paralytic, motionless, sluggish, still, static, inert.
meaningless (adjective)
hollow.
motionless (adjective)
unmoving, inert, quiet, motionless, sleeping, inactive, immobile, still, standing, vegetative, stagnant, languid, calm, fixed, becalmed, dormant, tranquil, dead, Resting, static, stationary.
new (adjective)
unused.
passive (adjective)
submissive, calm, complaisant, placid, acquiescent, inert, passive, inactive, yielding.
shallow (adjective)
shallow.
worthless, ineffective (adjective)
hollow, futile, empty, trivial, vain, rambling, pointless, groundless, useless, frivolous, otiose.

n.

vain, casual, complacency, slipshod, careless, perfunctory, remiss, complacent, like a bull in a china shop. faulty, inoperative, purposeless, worthless, inefficient, defective, useless, ineffective, pathetic, action. off-duty, subdued, sluggard, industrious, do-nothing, underemployed, shiftless, available. disused, full, sparing, at full stretch, economy, disuse, untapped, economical, hollow, devoted. true, bottomless, half-assed, supine. empty (noun)
rambling, vain, futile, trivial, pointless, shallow.
idle (noun)
lackadaisical, otiose, unwarranted, goldbricking, slothful, lazy, baseless, inactive, loose, irresponsible, indolent, unprofitable, unsupported, work-shy, laze, unfounded, light, stagnate, frivolous, leisure, unengaged, bone-idle, jobless, faineant, bone-lazy, out of work, unused, slug, groundless, at liberty, dead, leisured.
lazy (noun)
shiftless.

v.

stagnate (verb)
rest, hibernate, stop, immobilize, stagnate.

Other synonyms:

off-duty, sparing, subdued, disused, untapped, disuse, underemployed. cycle, shallow, inoperative, bottomless, backfire, shiftless, do-nothing, available. devoted, grind, burn up. fire, engagement. flood, economical, hollow, empty. economy. go. idle
fallow.
lazy
lazy.
rest
Resting.
stagnate
hibernate.
tie
immobilize.
Other relevant words:
inefficient, ineffective, sluggard, uncultivated, groundless, irresponsible, frivolous, goldbricking, rusty, unfounded, leisure, barren, sparing, laze, do-nothing, work-shy, economy, remiss, abandoned, trivial, fallow, slothful, pointless, rambling, deserted, careless, out of work, unsupported, otiose, leisured, lackadaisical, Workless, void, untapped, shiftless, bone-lazy, unprofitable, light, bottomless, untouched, purposeless, inoperative, underemployed, lazy, indolent, shallow, unused, grind, at liberty, unwarranted, faineant, down, dusty, unengaged, vain, slug, supine, available, loose, bone-idle, empty, futile, worthless, useless, cycle, hollow, go, baseless, backfire.

Usage examples for idle

  1. But it would not do to keep her sitting there with an idle pen in her hand. – The House of Martha by Frank R. Stockton
  2. In the meantime the men had not been idle – The Portland Sketch Book by Various
  3. There was mischief ready- made for idle hands to do. – From Sail to Steam, Recollections of Naval Life by Captain A. T. Mahan