persistence

Concise Oxford English Dictionary © 2008 Oxford University Press:
persistent/pəˈsɪstənt/

▶adjective

• 1 persisting or having a tendency to persist.

• 2 continuing or recurring; prolonged.

• 3 Botany & Zoology (of a part of an animal or plant, such as a horn, leaf, etc.) remaining attached instead of falling off in the normal manner.

– derivatives
persistence noun,
persistency noun,
persistently adverb.