Persistence

persistence |pərˈsistəns|
noun
firm or obstinate continuance in a course of action in spite of difficulty or opposition : companies must have patience and persistence, but the rewards are there.
• the continued or prolonged existence of something : the persistence of huge environmental problems.
DERIVATIVES
persistency |-sē| noun
ORIGIN mid 16th cent.: from French persistance, from the verb persister; influenced in spelling by Latin persistent- ‘continuing steadfastly.’