Persistent
Persistent , adjective
[Latin persistens, -entis, present participle of persistere. See Persist.]
1.
Inclined to persist; having staying qualities; tenacious of position or purpose.
2.
(Biology) Remaining beyond the period when parts of the same kind sometimes fall off or are absorbed; permanent; as, persistent teeth or gills; a persistent calyx; -- opposed to deciduous, and caducous.