equilibrium

A state in which different effects balance each other, so the overall situation does not change.

• The system reached equilibrium.
• A change in demand disturbed the market's equilibrium.
• The island's animal populations remained in equilibrium for years.

How to use it: in equilibrium (Supply and demand are in equilibrium.); equilibrium between A and B (The policy aims for equilibrium between spending and income.)

Similar words: balance, stability

Opposites: imbalance, disequilibrium

Common phrases: reach equilibrium, stable equilibrium, market equilibrium

A state in which all forces on an object balance, so its speed and direction do not change.

• The object is in equilibrium.
• Equal forces kept the beam in equilibrium.
• A moving object can remain in equilibrium if its velocity stays constant.

How to use it: in equilibrium (The hanging weight is in equilibrium.)

Similar words: mechanical balance

Opposites: disequilibrium

Common phrases: mechanical equilibrium, static equilibrium, in equilibrium

A state where opposite chemical reactions happen equally fast, so the amounts of the substances stay the same.

• The reaction reached equilibrium.
• Heating the mixture changed its chemical equilibrium.
• At equilibrium, the amounts of these chemicals remain constant.

How to use it: at equilibrium (At equilibrium, both reactions proceed at the same rate.)

Similar words: chemical balance

Common phrases: chemical equilibrium, equilibrium mixture, reach equilibrium

A calm, steady state of mind, even when things are difficult.

• She soon regained her equilibrium.
• A quiet walk helped restore his emotional equilibrium.
• The sudden news disturbed my equilibrium for several days.

Similar words: composure, mental balance, calm

Common phrases: mental equilibrium, emotional equilibrium, regain equilibrium