Persistent

1. Obstinately refusing to give up or let go.
2. Insistently repetitive.
3. Indefinitely continuous.
4. (botany) Lasting past maturity without falling off.
5. (computing) Of data or a data structure: not transient or temporary, but remaining in existence after the termination of the program that creates it.
6. (mathematics) Describing a fractal process that has a positive Brown function
7. (mathematics, stochastic processes, of a state) non-transient.