Other forms: persistingly
The adjective persisting is good for describing something that just won't go away, like a question or problem. If there is a persisting construction noise next door, you might need to buy some earplugs.
What do persisting, insist, and assist all have in common? The persisting sist, which comes from the Latin word sistere, meaning "stand." If you assist someone, you stand by them; if you insist on something, you stand up for it; and if you are persisting in doing something, you refuse to sit down.