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
• equilibration

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

Rather than aiming for a constant fixed equilibrium, dynamic leadership is about ongoing adjustments. —Iese Business School, Forbes.com, 10 July 2025

His ostentatious well-being is scorned by Walker, who equates equilibrium with compromise. —Los Angeles Times, 8 July 2025

Johnson has publicly and privately urged his Senate counterparts to make as few changes as possible to the bill, underscoring the importance of maintaining the tenuous equilibrium of support in the House. —Mike Lillis, The Hill, 4 June 2025

But finding the equilibrium between sultry world-building and enough visibility to read the menu is a delicate business. —Maggie Hennessy, Bon Appetit Magazine, 4 June 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

Rhymes for equilibrium

• disequilibrium
• nonequilibrium

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