noun. The lagging of an effect behind its cause, as when the change in magnetism of a body lags behind changes in the magnetic field.

noun. A lagging of one of two related phenomena behind the other.

noun. A lagging or retardation of the effect, when the forces acting upon a body are changed, as if from velocity or internal friction; a temporary resistance to change from a condition previously induced, observed in magnetism, thermoelectricity, etc., on reversal of polarity.

noun. A property of a system such that an output value is not a strict function of the corresponding input, but also incorporates some lag, delay, or history dependence, and in particular when the response for a decrease in the input variable is different from the response for an increase. For example, a thermostat with a nominal setpoint of 75° might switch the controlled heat source on when the temperature drops below 74°, and off when it rises above 76°.

noun. the lagging of an effect behind its cause; especially the phenomenon in which the magnetic induction of a ferromagnetic material lags behind the changing magnetic field

"Such systems often exhibit hysteresis, that is multiple states for the same system parameters but which state you are in depends on history, i.e., initial conditions."