equilibrium
/ˌiːkwɪˈlɪbrɪəm
/ /ˌɛkwɪˈlɪbrɪəm/noun (plural equilibria /ˌiːkwɪˈlɪbrɪə/ /ˌɛkwɪˈlɪbrɪə/) [mass noun]
1A state in which opposing forces or influences are balanced: the task is the maintenance of social equilibrium...
- A dynamic and nearly balanced equilibrium between opposing forces appears to characterize the situation.
- The unsustainable nature of psi is consistent with the concept that psi effects are a dynamic or fluctuating equilibrium between opposing forces.
- This analysis suggested that the African population is close to equilibrium between mutational forces and genetic drift.
Synonyms
balance, symmetry, equipoise, parity, equality, evenness;
stability, steadiness
archaic counterpoise, equipollence
1.1A state of physical balance: I stumbled over a rock and recovered my equilibrium...
- An orderly life includes mental as well as physical equilibrium, and shunning all evil thoughts.
- Earth, unlike the other solar planets, is not in physical equilibrium.
- Once detached from the gland and ring, respectively, the cell and bubble become spherical to achieve physical equilibrium.
1.2A calm state of mind: his intensity could unsettle his equilibrium...
- It might appear from the above that postures, breathing techniques and sensory control automatically purge the mind of distractions and bring about equilibrium and calm.
- I certainly felt bound to the river for restoring my equilibrium, for calming my senses and for providing me with an escape from the city.
- He'd clearly achieved equilibrium as he calmed down until, noticing he wasn't packing his stuff, the checkout woman tried to help him.
Synonyms
composure, calmness, calm, equanimity, collectedness, sangfroid, coolness;
steadiness, stability, level-headedness, cool-headedness, imperturbability, poise, presence of mind;
self-possession, self-control, self-command;
impassiveness, impassivity, unexcitability, placidity, placidness, tranquillity, serenity
informal cool, unflappability
rare ataraxy, ataraxia
1.3 Chemistry A state in which a process and its reverse are occurring at equal rates so that no overall change is taking place: ice is in equilibrium with water...
- The maximum concentration of ions in the solution is in equilibrium with the precipitated solid.
- Therefore, the metastable equilibrium between iron and iron carbide should be considered, because it is relevant to the behavior of most steels in practice.
- The current ozone layer is as a result of equilibrium between breakdown and recombination.
1.4 Economics A situation in which supply and demand are matched and prices stable: the market is in equilibrium [as modifier]: the equilibrium level of income...
- There has been a huge increase in supply and now the levels of supply and demand are in equilibrium.
- In such a model, prices are in equilibrium at every moment, even when equilibrium prices are changing over time.
- There appears to be equilibrium in demand supply.
Derivatives
equilibrial
- Cenozoic mammals of North America exhibited equilibrial diversity for approximately 55 Myr (Eocene-Pleistocene), with strong local interactions limiting diversity in local assemblages.
- If mortality schedules subsequent to recruitment are strongly density-dependent, pulses of high recruitment will be followed by enhanced mortality and the standing population will remain at or close to an equilibrial size.
- Some of the chapter authors refine these definitions somewhat to reflect current usage, for example, defining a regulated population in terms of a stationary probability distribution rather than an equilibrial density.
Origin
Early 17th century (in the sense 'well-balanced state of mind'): from Latin aequilibrium, from aequi- 'equal'+ libra 'balance'.