-persistency-

{ } n. [ See Persistent. ] 1. The quality or state of being persistent; staying or continuing quality; hence, in an unfavorable sense, doggedness; obstinacy. [ 1913 Webster ]

2. The continuance of an effect after the cause which first gave rise to it is removed; as: (a) (Physics) The persistence of motion. (b) (Physiol.) Visual persistence, or persistence of the visual impression; auditory persistence, etc. [ 1913 Webster ]