Never dating, wife leaves unpaid (7)
I believe the answer is:
ageless
'unpaid' is the definition.
Both the answer and definition are adjectives. Perhaps you can see an association between them that I can't see?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for ageless that I've seen before include "not appearing to get old" , "Not appearing to grow older" , "not getting on" , "Not growing older" , "Lasting forever" .)