Persistency

Definition:

(n.) The quality or state of being persistent; staying or continuing quality; hence, in an unfavorable sense, doggedness; obstinacy.
(n.) The continuance of an effect after the cause which first gave rise to it is removed
(n.) The persistence of motion.
(n.) Visual persistence, or persistence of the visual impression; auditory persistence, etc.

Compare persistency with other words:

consistency vs. persistency