- When something is at equilibrium, it is balanced and different types of influences are the same, hence having no net change.
- The population of the ants in this area has reached an equilibrium.
- (physics) When an object is at equilibrium, it is at rest or continuous motion and all the forces acting on it cancels out to become zero.
- Antonym: disequilibrium
- (chemistry) When a system is in equilibrium, the rates of the forward and backward reactions are the same, hence causing no change in the concentration of the reactants and products.
- When a weak acid is added into water, an equilibrium mixture is obtained.