Net diver turned upside down (8)
I believe the answer is:
inverted
'upside down' is the definition.
(I've seen this before)
'net diver turned' is the wordplay.
'turned' indicates anagramming the letters.
'net'+'diver'='netdiver'
'netdiver' anagrammed gives 'INVERTED'.
(Other definitions for inverted that I've seen before include "Upturned" , "Upside-down" , "Turned upside down" .)