noun.
In electricity, the time-constant of a circuit in which current is beginning to flow; the time required for an electric current to rise to or .634 of its final value.
noun.
The quality of being persistent; steady or firm adherence to or continuance in state, course of action, or pursuit that has been entered upon; especially (of persons), a more or less obstinate perserverance; perserverance notwithstanding opposition, warning, remonstrane, etc.
noun.
2. The continuance of an effect after the cause which first gave rise to it is removed: as, the persistence of the impression of light on the retina after the luminous object is withdrawn; the persistence of force.