Decent, having son do well (7)
I believe the answer is:
prosper
'do well' is the definition.
(I've seen this in another clue)
'decent having son' is the wordplay.
I cannot quite understand how this works, but
'son' could be 's' (genealogical abbreviation for son) and 's' is located in the answer.
'decent' could be 'proper' (associated in meaning) and 'proper' is found in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for prosper that I've seen before include "Succeed, flourish" , "Make good" , "Do well, be successful in life" , "Thrive, boom" , "Flourish, do well" .)