Belgian translated an Asian language (7)
I believe the answer is:
bengali
'an asian language' is the definition.
(I've seen this in another clue)
'belgian translated' is the wordplay.
'translated' is an anagram indicator.
'belgian' with letters rearranged gives 'BENGALI'.
(Other definitions for bengali that I've seen before include "Asian language" , "foreign language" , "Asian character" , "may be Indian" , "Language of Bangladesh and northeast India" .)