persisˈtence or persisˈtency noun

1. The quality of being persistent
2. Perseverance
3. Obstinacy
4. Duration, esp of an effect after the stimulus has been removed, eg of a cathode-ray tube

persisˈtent adjective

1. Persisting
2. Pushing on, esp against opposition
3. Tenacious
4. Fixed
5. Constant or constantly repeated
6. Remaining after the usual time of falling off, withering, or disappearing (zoology; botany)
7. Continuing to grow beyond the usual time
8. Remaining relatively stable after release into the environment (chem)

A person or thing that is persistent

persisˈtently adverb

persisˈtingly adverb

persisˈtive adjective (Shakespeare)

Persistent

persistent cruelty noun (law; in matrimonial proceedings)

Behaviour likely to cause danger to the life or health of a spouse

persistent vegetative state noun (medicine)

An irreversible condition induced by lack of oxygen, in which the sufferer is still alive, but is incapable of any thought processes and any voluntary physical action (abbrev PVS)