Much of North Africa (6)
I believe the answer is:
sahara
'much of north africa' 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 "About 3,500,000 square miles of Africa" , "World's largest sandy area" , "Great desert in N Africa" , "Hottest desert" , "Uncultivated region of north Africa" .)