Possible Clues:

• Prettiness in a constantly recurring form
• Not giving up
• It's present in a constantly recurring form
• A nun that's abridged religious work is diligent
• Tenacious priest sent abroad
• Tenacious; constant
• Not letting go
• Going on and on, stupidly resist 'Shut up about!'
• Unrelenting - prettiness (anag)
• Dogged badger nips setter