equilibrium

noun

equi·​lib·​ri·​um ˌē-kwə-ˈli-brē-əm  ˌe- 

plural equilibriums or equilibria ˌē-kwə-ˈli-brē-ə 

ˌe-

1

a

: a state of intellectual or emotional balance : poise

trying to recover his equilibrium

b

: a state of adjustment between opposing or divergent influences or elements

2

: a state of balance between opposing forces or actions that is either static (as in a body acted on by forces whose resultant is zero) or dynamic (as in a reversible chemical reaction when the rates of reaction in both directions are equal)

3

: balance sense 3a

Did you know?

Equilibrium contains a root from the Latin libra, meaning "weight" or "balance". As a constellation, zodiac symbol, and astrological sign, Libra is usually pictured as a set of balance scales, often held by the blindfolded goddess of justice, which symbolizes fairness, equality, and justice. Equilibrium has special meanings in biology, chemistry, physics, and economics, but in all of them it refers to the balance of competing influences.

Synonyms

• balance
• counterpoise
• equilibration
• equipoise
• poise
• stasis

Examples of equilibrium in a Sentence

Supply and demand were in equilibrium.

we must find an equilibrium between commercial development and conservation of our natural treasures

Recent Examples on the Web

The calming formula is infused with an antioxidant-rich blend of mugwort, green tea, and panthenol to bring your skin back to a comfortable, irritation-free equilibrium. —Devon Abelman, Allure, 11 Feb. 2025

After a certain period of time in deep water, the inert gases breathed in by a diver, or in this case, a sentinel resident, dissolve into body tissues and eventually reach an equilibrium with the pressure in their particular depth. —Mack Degeurin, Popular Science, 5 Feb. 2025

The future of international trade will depend on our ability to maintain this delicate equilibrium. —Robert Daugherty, Forbes, 23 Jan. 2025

But the equilibrium that Zuck has shot for, with Facebook and with Instagram, has been a service that is nearly so bad that people want to leave. —Allison Morrow, CNN, 13 Jan. 2025

Word History

Etymology

Latin aequilibrium, from aequilibris being in equilibrium, from aequi- + libra weight, balance

First Known Use

1608, in the meaning defined at sense 1a

Phrases Containing equilibrium

• equilibrium constant
• punctuated equilibrium

Kids Definition

equilibrium

noun

equi·​lib·​ri·​um ˌē-kwə-ˈlib-rē-əm 

ˌek-wə-

plural equilibriums or equilibria -rē-ə 

1

: a state of balance between opposing forces or actions

2

: the normal balanced state of the body of an animal that is maintained in relation to the forces (as gravity) acting on it and to things in the environment (as the surface on which life is lived) and that is sensed and checked by the inner ear of vertebrates including human beings

Etymology

from Latin aequilibrium "state of being in balance," from aequus "equal" and libra "weight, balance, scales" — related to deliberate, libra

Medical Definition

equilibrium

noun

equi·​lib·​ri·​um ˌē-kwə-ˈlib-rē-əm  ˌek-wə- 

plural equilibriums or equilibria -rē-ə 

1

: a state of balance between opposing forces or actions that is either static (as in a body acted on by forces whose resultant is zero) or dynamic (as in a reversible chemical reaction when the velocities in both directions are equal)

2

: a state of intellectual or emotional balance