Flat land is not beautiful (5)
I believe the answer is:
plain
'flat land' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for plain that I've seen before include "Unflavoured" , "ugly" , "Evident; not fancy" , "Uncomplicated" , "Simple - flatland" .)