Continuing firmly or obstinately in an opinion or course of action in spite of difficulty or opposition
he's a very persistent man
That does not persist, especially in the course of phylogeny or ontogeny, or in the environment; (Botany) designating or relating to plant viruses that are carried only briefly and superficially on the mouthparts of insect vectors (also called non-circulative).
A hazardous organic chemical compound that is resistant to biodegradation and thus remains in the environment for a long period of time
A condition in which a medical patient is completely unresponsive to psychological and physical stimuli and displays no sign of higher brain function, being kept alive only by medical intervention