- having no inherent ability to move or to resist motion
- inactive, lazy, or sluggish
- having only a limited ability to react chemically; unreactive
WordReference Random House Learner's Dictionary of American English © 2026
in•ert /ɪnˈɜrt/USA pronunciation
adj.
in•ert•ness, n. [uncountable]
WordReference Random House Unabridged Dictionary of American English © 2026- having no power of action (opposed to active):inert matter.
- Chemistry(of chemical substances) having little or no ability to react in a chemical reaction:Nitrogen is an inert gas.
- inactive or sluggish:He stood inert as we rushed toward her.
in•ert•ness, n. [uncountable]
in•ert
(in ûrt′, i nûrt′),USA pronunciation adj.
in•ert′ly, adv.
in•ert′ness, n.
- having no inherent power of action, motion, or resistance (opposed to active):inert matter.
- Chemistryhaving little or no ability to react, as nitrogen that occurs uncombined in the atmosphere.
- Drugs[Pharm.]having no pharmacological action, as the excipient of a pill.
- inactive or sluggish by habit or nature.
- Latin inert- (stem of iners) unskillful, equivalent. to in- in-3 + -ert-, combining form of art- (stem of ars) skill; see art1
- 1640–50
in•ert′ness, n.
- 1. immobile, unmoving, lifeless, motionless. 4. See inactive.
Collins Concise English Dictionary © HarperCollins Publishers::
inert /ɪnˈɜːt/ adj