Sarah travelled a desert (6)
I believe the answer is:
sahara
'desert' is the definition.
(I know that Sahara is a desert)
'sarah travelled a' is the wordplay.
'travelled' indicates an anagram.
'sarah' anagrammed gives 'sahar'.
'sahar'+'a'='SAHARA'
(Other definitions for sahara that I've seen before include "About 3,500,000 square miles of Africa" , "World's largest desert" , "Hottest desert" , "World's largest sandy area" , "Uncultivated region of north Africa" .)