1. Refusing to give up or let go; persevering obstinately.

2. Insistently repetitive or continuous: a persistent honking of car horns.

3. Existing or remaining in the same state for an indefinitely long time; enduring: persistent rumors; a persistent infection.

4. Botany Lasting past maturity without falling off, as the calyx on an eggplant or the scales of a pine cone.

5. Zoology Retained permanently, rather than disappearing in an early stage of development: the persistent gills of fishes.