noun pl. equilibriums -·ri·ums or equilibria -·ria (-ə)

1. a state of balance or equality between opposing forces
2. a state of balance or adjustment of conflicting desires, interests, etc.
3. 1. the ability of the animal body to keep itself properly oriented or positioned; bodily stability or balance
   2. mental or emotional stability or balance; poise
4. the condition in a reversible chemical reaction in which the products of the reaction are consumed by the reverse reaction at the same rate as they are formed, and there is no net change in the concentrations of the products or the reactants
5. the stage of a radioactive material at which the rate of disintegration and the rate of formation are equal for each intermediate product in the radioactive decay series

Etymology: L aequilibrium < aequilibris, evenly balanced < aequus (see equal) + libra, a balance