Largest desert (6)
I believe the answer is:
sahara
'largest desert' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sahara that I've seen before include "Uncultivated region of north Africa" , "About 3,500,000 square miles of Africa" , "World's largest sandy area" , "Great African desert" , "Great desert in N Africa" .)