Hint: it's a Chinese dynasty (4)
I believe the answer is:
tang
I believe this is a double definition.
'hint' is the first definition.
(thesaurus)
'a chinese dynasty' is the second definition.
(I've seen this before)
'it's' acts as a link.
(Other definitions for tang that I've seen before include "Piquancy - Chinese dynasty" , "Tart spiciness" , "Savour" , "Tart taste and Chinese dynasty" , "characteristic quality" .)