[ in-ak-tiv ]
/ ɪnˈæk tɪv /


not active: an inactive volcano.
sedentary or passive: an inactive life.
sluggish; indolent.
Military. not on active duty.
  1. inert; unreactive.
  2. noting a compound that has no effect on polarized light.

Nearby words

  1. inaccuracy,
  2. inaccurate,
  3. inaction,
  4. inactivate,
  5. inactivated poliovirus vaccine,
  6. inactive repressor,
  7. inactively,
  8. inactivity,
  9. inadequacy,
  10. inadequate

Origin of inactive

First recorded in 1715–25; in-3 + active

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.

Related formsin·ac·tive·ly, adverbin·ac·tiv·i·ty, in·ac·tive·ness, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for inactive

British Dictionary definitions for inactive


/ (ɪnˈæktɪv) /


idle or inert; not active
sluggish, passive, or indolent
military of or relating to persons or equipment not in active service
chem (of a substance) having little or no reactivity
(of an element, isotope, etc) having little or no radioactivity
Derived Formsinactively, adverbinactivity or inactiveness, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for inactive



1725, from in- (1) "not, opposite of" + active.

Online Etymology Dictionary, © 2010 Douglas Harper