Sculpture of T'ang empire is steep (10)
I believe the answer is:
impregnate
'is steep' is the definition.
(thesaurus)
'sculpture of t'ang empire' is the wordplay.
'sculpture of' indicates an anagram (I've seen 'sculpture' mean this).
'tang'+'empire'='tangempire'
'tangempire' is an anagram of 'IMPREGNATE'.
(Other definitions for impregnate that I've seen before include "Saturate with a substance" , "Fill" , "soak" , "Saturate - permeating (anag)" , "Infuse" .)