1.  inactivity(n = noun.state) inaction, inactiveness - the state of being inactive;
is a kind of state
has particulars: abeyance, suspension, anergy, arrest, check, halt, hitch, stay, stop, stoppage, calcification, deep freeze, desuetude, dormancy, quiescence, quiescency, extinction, holding pattern, rest, doldrums, stagnancy, stagnation, stagnancy, stagnation, stasis
Antonym: activity
Derived forms adjective inactive₅, adjective inactive₁₀, adjective inactive₁

2.  inactivity(n = noun.attribute) inactiveness, inertia - a disposition to remain inactive or inert; "he had to overcome his inertia and get back to work"
is a kind of trait
has particulars: flatness, languor, lethargy, phlegm, sluggishness, restfulness, passiveness, passivity, indolence, laziness
Derived form adjective inactive₆

3.  inactivity(n = noun.act) - being inactive; being less active;
is a kind of act, deed, human action, human activity
has particulars: pause, wait, waiting, ease, relaxation, repose, rest, idleness, idling, loafing, delay, holdup
Antonym: activity
Derived forms adjective inactive₈, adjective inactive₇

1.  The state or quality of being inactive; inertness; as, the inactivity of matter. [1913 Webster]

2.  Idleness; habitual indisposition to action or exertion; lack of energy; sluggishness. [1913 Webster]
"The gloomy inactivity of despair." [1913 Webster]

N  inaction, passiveness, abstinence from action, noninterference, nonintervention, Fabian policy, conservative policy, neglect, inactivity, rest, quiescence, want of occupation, inoccupation, idle hours, time hanging on one's hands, dolce far niente, sinecure, featherbed, featherbedding, cushy job, no-show job, soft snap, soft thing, not doing, not done, undone, passive, unoccupied, unemployed, out of employ, out of work, fallow, desaeuvre, re infecta, at a stand, les bras croisis, with folded arms, with the hands in the pockets, with the hands behind one's back, pour passer le temps, Int, so let it be!, stop!, hands off!, cunctando restituit rem, If it ain't broke don't fix it, stare decisis, let the decision stand.

N  inactivity, inaction, inertness, obstinacy, lull, quiescence, rust, rustiness, idleness, remissness, sloth, indolence, indiligence, dawdling, ergophobia, otiosity, dullness, languor, segnity, segnitude, lentor, sluggishness, procrastination, torpor, torpidity, torpescence, stupor, somnolence, drowsiness, nodding, oscitation, oscitancy, pandiculation, hypnotism, lethargy, statuvolence heaviness, heavy eyelids, sleep, slumber, sound sleep, heavy sleep, balmy sleep, Morpheus, Somnus, coma, trance, ecstasis, dream, hibernation, nap, doze, snooze, siesta, wink of sleep, forty winks, snore, hypnology, dull work, pottering, relaxation, Castle of Indolence, lullaby, sedative, tranquilizer, hypnotic, sleeping pill, relaxant, anaesthetic, general anaesthetic, torpedo, idler, drone, droil, dawdle, mopus, do- little faineant, dummy, sleeping partner, afternoon farmer, truant, bummer, loafer, goldbrick, goldbicker, lounger, lazzarone, lubber, lubbard, slow coach (slow, ), opium eater, lotus eater, slug, lag, sluggard, slugabed, slumberer, dormouse, marmot, waiter on Providence, fruges consumere natus, inactive, motionless, unoccupied, unbusied, indolent, lazy, slothful, idle, lusk, remiss, slack, inert, torpid, sluggish, otiose, languid, supine, heavy, dull, leaden, lumpish, exanimate, soulless, listless, drony, dronish, lazy as Ludlam's dog, dilatory, laggard, lagging, slow, rusty, flagging, lackadaisical, maudlin, fiddle-faddle, pottering, shilly-shally, sleeping asleep, fast asleep, dead asleep, sound asleep, in a sound sleep, sound as a top, dormant, comatose, in the arms of Morpheus, in the lap of Morpheus, sleepy, sleepful, dozy, drowsy, somnolent, torpescent, lethargic, lethargical, somnifacient, statuvolent, statuvolic, heavy, heavy with sleep, napping, somnific, somniferous, soporous, soporific, soporiferous, hypnotic, balmy, dreamy, unawakened, unawakened, sedative, inactively, at leisure, the eyes begin to draw straws, bankrupt of life yet prodigal of ease, better 50 years of Europe than a cycle of Cathay, idly busy rolls their world away, the mystery of folded sleep, the timely dew of sleep, thou driftest gently down the tides of sleep, tired Nature's sweet restorer, balmy sleep.

N  weakness, debility, atony, relaxation, languor, enervation, impotence, infirmity, effeminacy, feminality, fragility, flaccidity, inactivity, anaemia, bloodlessness, deficiency of blood, poverty of blood, declension of strength, loss of strength, failure of strength, delicacy, invalidation, decrepitude, asthenia, adynamy, cachexy, cachexia, sprain, strain, reed, thread, rope of sand, house of cards, softling, weakling, infant, youth, weak, feeble, debile, impotent, relaxed, unnerved sapless, strengthless, powerless, weakly, unstrung, flaccid, adynamic, asthenic, nervous, soft, effeminate, feminate, womanly, frail, fragile, shattery, flimsy, unsubstantial, insubstantial, gimcrack, gingerbread, rickety, creaky, creaking, cranky, craichy, drooping, tottering, broken, lame, withered, shattered, shaken, crazy, shaky, palsied, decrepit, languid, poor, infirm, faint, faintish, sickly, dull, slack, evanid, spent, short-winded, effete, weather-beaten, decayed, rotten, worn, seedy, languishing, wasted, washy, laid low, pulled down, the worse for wear, unstrengthened, unsupported, unaided, unassisted, aidless, defenseless, cantilevered (support), on its last legs, weak as a child, weak as a baby, weak as a chicken, weak as a cat, weak as a rat, weak as water, weak as water gruel, weak as gingerbread, weak as milk and water, colorless, non sum qualis eram.

N  physical inertness, inertness, dullness, inertia, vis inertiae, inertion, inactivity, torpor, languor, quiescence, latency, inaction, passivity, mental inertness, sloth, inexcitability, irresolution, obstinacy, permanence, rare gas, paraffin, noble metal, unreactivity, inert, inactive, passive, torpid, sluggish, dull, heavy, flat, slack, tame, slow, blunt, unreactive, lifeless, dead, uninfluential, latent, dormant, smoldering, unexerted, inactively, in suspense, in abeyance.