The world's largest hot desert (6)
I believe the answer is:
sahara
'the world's largest hot desert' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sahara that I've seen before include "World's largest sandy area" , "Great African desert" , "North African desert" , "Great desert in N Africa" , "World's largest desert" .)