From rear, the nude's made of clay (7)
I believe the answer is:
earthen
'made of clay' is the definition.
(I've seen this before)
'from rear the nude's' is the wordplay.
'from' indicates a hidden word.
'EARTHEN' is hidden in the letters of 'rear the nudes'.
(Other definitions for earthen that I've seen before include "of the soil" , "Made of baked or fired clay" , "Like many pots" , "(Of a pot) made of fired clay" , "Made of baked clay, perhaps ware" .)