| 1. | the lag in response exhibited by a body in reacting to changes in the forces, esp. magnetic forces, affecting it. Compare magnetic hysteresis. |
| 2. | the phenomenon exhibited by a system, often a ferromagnetic or imperfectly elastic material, in which the reaction of the system to changes is dependent upon its past reactions to change. |

hysteresis hys·ter·e·sis (hĭs'tə-rē'sĭs)
n. pl. hys·ter·e·ses (-sēz)
The lagging of an effect behind its cause, as when the change in magnetism of a body lags behind changes in the magnetic field.