Live and thrive, having lost nothing (5)
I believe the answer is:
dwell
'live' is the definition.
(to live/dwell somewhere)
'and thrive having lost nothing' is the wordplay.
'and' becomes 'n' (common abbreviation for 'and').
'thrive' becomes 'do well' (I've seen this in another clue).
'having lost' suggests deleting specific letters.
'nothing' becomes 'no' (similar in meaning).
'n'+'dowell'='ndowell'
'ndowell' with 'no' removed is 'DWELL'.
(Other definitions for dwell that I've seen before include "Live (in a place)" , "Inhabit" , "Remain" , "Exist (within)" , "Settle" .)