Inertia \In*er"ti*a\, n. [L., idleness, fr. iners idle. See Inert.]

[1913 Webster]

1. (Physics) That property of matter by which it tends when at rest to remain so, and when in motion to continue in motion, and in the same straight line or direction, unless acted on by some external force; -- sometimes called vis inerti[ae]. The inertia of a body is proportional to its mass. [1913 Webster +PJC]

2. Inertness; indisposition to motion, exertion, or action; lack of energy; sluggishness. [1913 Webster]

Men . . . have immense irresolution and inertia. --Carlyle. [1913 Webster]

3. (Med.) Lack of activity; sluggishness; -- said especially of the uterus, when, in labor, its contractions have nearly or wholly ceased. [1913 Webster]

Center of inertia. (Mech.) See under Center. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

112 Moby Thesaurus words for "inertia": a wise passiveness, abeyance, apathy, catalepsy, catatonia, cautiousness, circumspection, contemplation, contemplative life, creeping, deadliness, deathliness, deliberateness, deliberation, dilatoriness, do-nothing policy, do-nothingism, do-nothingness, dormancy, drawl, dullness, entropy, ergophobia, faineancy, faineantise, firmness, foot-dragging, hibernation, hoboism, idleness, immobility, immobilization, immovability, immovableness, inaction, inactiveness, inactivity, indifference, indolence, inertness, inexertion, inextricability, inflexibility, irremovability, just being, laggardness, laissez-aller, laissez-faire, laissez-faireism, languor, lassitude, latency, laziness, leisureliness, lentitude, lentor, listlessness, lotus-eating, lull, meditation, mere existence, mere tropism, motionlessness, neutralism, neutrality, neutralness, noninvolvement, nonparticipation, nonresistance, nonviolence, nonviolent resistance, pacifism, paralysis, passive resistance, passive self-annihilation, passiveness, passivism, passivity, pokiness, policy, procrastination, quiescence, quietism, reluctance, remissness, rigidity, shiftlessness, slackness, sloth, slothfulness, slowness, sluggardy, sluggishness, solidity, spring fever, stagnancy, stagnation, standpattism, stasis, suspense, suspension, tentativeness, torpor, underactivity, unmovability, unyieldingness, vagrancy, vegetation, vis inertiae, vita contemplativa, waiting game, watching and waiting

Source: Moby Thesaurus II by Grady Ward, 1.0
 

inertia

Source: WordNet (r) 2.0
 

Inertia \In*er"ti*a\, n. [L., idleness, fr. iners idle. See Inert.]

1. (Physics) That property of matter by which it tends when at rest to remain so, and when in motion to continue in motion, and in the same straight line or direction, unless acted on by some external force; -- sometimes called vis inerti[ae].

2. Inertness; indisposition to motion, exertion, or action; want of energy; sluggishness.

Men . . . have immense irresolution and inertia. --Carlyle.

3. (Med.) Want of activity; sluggishness; -- said especially of the uterus, when, in labor, its contractions have nearly or wholly ceased.

Center of inertia. (Mech.) See under Center.

Source: Webster's Revised Unabridged Dictionary (1913)