Son au naturel, perhaps, got up (5)
I believe the answer is:
risen
'got up' is the definition.
('rise' can be a synonym of 'get up')
'son au naturel' is the wordplay.
I cannot really understand how this works, but
'son' could be 's' (genealogical abbreviation for son) and 's' is found in the answer.
The remaining letters 'rien' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'perhaps' is the link.
Can you help me to learn more?
(Other definitions for risen that I've seen before include "Sprung up" , "Gone up" , "Grown up" , "Resin (anag.)" , "(Of sun) up" .)