Pakistani's language (4)
I believe the answer is:
urdu
'pakistani's language' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for urdu that I've seen before include "Sanskrit language" , "Language spoken by Moslems in Pakistan and India" , "Sub-continental language" , "Language used in Pakistan, India" , "One of official languages of Pakistan" .)