- idle or inert; not active
- sluggish, passive, or indolent
- of or relating to persons or equipment not in active service
- (of a substance) having little or no reactivity
- (of an element, isotope, etc) having little or no radioactivity
WordReference Random House Learner's Dictionary of American English © 2026
in•ac•tive /ɪnˈæktɪv/USA pronunciation
adj. quiet; not doing much:an inactive, boring retirement.
[Military.]not on active duty.
in•ac•tiv•i•ty /ˌɪnækˈtɪvɪti/USA pronunciation n. [uncountable]a boring inactivity once he retired.
WordReference Random House Unabridged Dictionary of American English © 2026- not active:an inactive volcano.
in•ac•tive
(in ak′tiv),USA pronunciation adj.
in•ac′tive•ly, adv.
in′ac•tiv′i•ty, in•ac′tive•ness, n.
- not active:an inactive volcano.
- sedentary or passive:an inactive life.
- sluggish;
indolent. - [Mil.]not on active duty.
- Chemistry
- inert;
unreactive. - noting a compound that has no effect on polarized light.
- inert;
- in-3 + active 1715–25
in′ac•tiv′i•ty, in•ac′tive•ness, n.
- 1. unmoving, immobile, inoperative. 1. 2. Inactive, dormant, inert, sluggish, torpid suggest lack of activity. Inactive indicates absence of action, indisposition to activity, or cessation of activity:an inactive compound, life, file of papers.Dormant suggests the quiescence or inactivity of that which sleeps but may be roused to action:a dormant volcano.Inert suggests the condition of dead matter, with no inherent power of motion or action; it may also mean unable to move, or heavy and hard to move:an inert mass; inert from hunger.Sluggish expresses slowness of natural activity or of that which does not move readily or vigorously:a sluggish stream, brain.Torpid suggests a state of suspended physical powers, a condition particularly of animals that hibernate:Snakes are torpid in cold weather. 3. lazy, idle, slothful.
- 1. –3. lively.
Collins Concise English Dictionary © HarperCollins Publishers::
inactive /ɪnˈæktɪv/ adj
'inactive' also found in these entries (note: many are not synonyms or translations):
alpha rhythm
- argon
- asleep
- benumb
- clump
- dormant
- down
- extinct
- fallow
- flat
- idle
- inactivate
- incubate
- inert
- Irish Republican Army
- languid
- latent
- pepsin
- placebo
- prodrug
- proenzyme
- provirus
- quiescent
- quiet
- shop
- sit
- sleep
- sluggish
- torpedo
- vegetable
- vehicle
- wait
- waken
- zymogen
- abeyant
- angiotensin
- carrier
- deactivate
- dead
- dull
- estivate
- flareup
- front
- inanimate
- indolent
- labile
- lazy
- lifeless
- lively
- mothball