ETYM Latin aequilibrium, from aequilibris in equilibrium, level; aequus equal + libra balance. Related to Equal, and Librate.
Translational) Condition in which the net force on an object is zero. (Rotational) Condition in which the net torque on an object is zero.1. A sensory system located in structures of the inner ear that registers the orientation of the head; SYN. labyrinthine sense, vestibular sense, sense of balance, sense of equilibrium.
2. A stable situation in which forces cancel one another.
In physics, an unchanging condition in which the forces acting on a particle or system of particles (a body) cancel out, or in which energy is distributed among the particles of a system in the most probable way. In accordance with Newton's first law of motion, a body in equilibrium remains at rest or moves with constant velocity; it does not accelerate.
A body is in thermal equilibrium with its surroundings if no heat enters or leaves it, so that all its parts are at the same temperature as the surroundings.