Former model principally depicted naked (7)
I believe the answer is:
exposed
'naked' is the definition.
(I've seen this before)
'former model principally depicted' is the wordplay.
'former' becomes 'ex'.
'model' becomes 'pose' ('pose' can be a synonym of 'model'**).
'principally' says to take the initial letters.
The first letter of 'depicted' is 'd'.
'ex'+'pose'+'d'='EXPOSED'
(Other definitions for exposed that I've seen before include "naked" , "Not covered" , "Made public" , "Like a dummy" , "Deprived of cover" .)