Learner's definition of PERSISTENT
[more persistent; most persistent]
continuing to do something or to try to do something even though it is difficult or other people want you to stop
We were nagged by a persistent salesman.
He is one of the government's most persistent critics.
She has been persistent in pursuing the job.
continuing beyond the usual, expected, or normal time
not stopping or going away
He has been fighting a persistent cold/infection.
Flooding has been a persistent problem in the area this year.
Persistent rumors that the business is for sale have alarmed the staff.