Not functioning or operating; out of use: inactive machinery.
Not being in continuous use or operation: an inactive brokerage account.
Retired from duty or service.
Chemistry Not readily participating in chemical reactions; inert.
Biology Marked by the absence or reduction of activity, such as the ability to cause infection.
Medicine Quiescent. Used especially of a disease.
Physics Showing no optical activity in polarized light.
derivatives
in·aćtive·ly
adverb
ińac·tiv́i·ty
noun
synonyms:
inactive, idle, inert, passive, dormant, torpid, supine These adjectives mean not involved in or disposed to movement or activity. Inactive simply indicates absence of activity: retired but not inactive; an inactive factory. Idle refers to persons who are not doing anything or are not busy: employees idle because of the strike. It also refers to what is not in use or operation: idle machinery. Inert describes things powerless to move themselves or to produce a desired effect; applied to persons, it implies lethargy or sluggishness, especially of mind or spirit: “The Honorable Mrs. Jamieson . . . was fat and inert, and very much at the mercy of her old servants” (Elizabeth C. Gaskell) Passive implies being reactive instead of proactive: “in an hour like this, when the mind has a passive sensibility, but no active strength” (Nathaniel Hawthorne) Dormant refers principally to a state of suspended activity but often implies the possibility of renewal: dormant feelings of affection. Torpid suggests sluggishness or apathy: “It is a man's own fault, it is from want of use, if his mind grows torpid in old age” (Samuel Johnson) Supine implies abject lack of will: “No other colony showed such supine, selfish helplessness in allowing her own border citizens to be mercilessly harried” (Theodore Roosevelt)
The American Heritage® Dictionary of the English Language, Fourth Edition