[ in-ak-tiv ]
See synonyms for: inactiveinactivelyinactivity on

  1. not active: an inactive volcano.

  2. sedentary or passive: an inactive life.

  1. sluggish; indolent.

  2. Military. not on active duty.

  3. Chemistry.

    • inert; unreactive.

    • noting a compound that has no effect on polarized light.

Origin of inactive

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

synonym study For inactive

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.

Other words for inactive

Opposites for inactive

Other words from inactive

  • in·ac·tive·ly, adverb
  • in·ac·tiv·i·ty, in·ac·tive·ness, noun

Words Nearby inactive Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use inactive in a sentence

British Dictionary definitions for inactive


/ (ɪnˈæktɪv) /

  1. idle or inert; not active

  2. sluggish, passive, or indolent

  1. military of or relating to persons or equipment not in active service

  2. chem (of a substance) having little or no reactivity

  3. (of an element, isotope, etc) having little or no radioactivity

Derived forms of inactive

  • inactively, adverb
  • inactivity 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