South Asian language (4)
'south asian 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 "Asian language written in Arabic script" , "Form of Hindustani" , "Pakistani language" , "Language closely related to Hindi" , "Indian language" .)
(Other definitions for hindi that I've seen before include "tongue" , "It's spoken abroad" , "Language of northern India" , "Language derived from Sanskrit" , "Indian language" .)
(Other definitions for tamil that I've seen before include "S. India/Sri Lankan person, tongue" , "One in race" , "Perhaps Indian" , "Member of South Indian people" , "Asian language" .)
(Other definitions for lao that I've seen before include "Indo-Chinese language" , "Asian" .)