Great river of south Asia (5)
I believe the answer is:
indus
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">great river of south asia</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for indus that I've seen before include "River of India and Pakistan" , "Punjab river" , "South Asian river" , "Important river" , "9 of Pakistan" .)