Flat-top - same only different (4)
I believe the answer is:
mesa
'flat' is the definition.
(thesaurus)
'same only different' is the wordplay.
'only different' indicates an anagram (I've seen this in other clues).
'same' with letters rearranged gives 'MESA'.
'top' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for mesa that I've seen before include "Flat hill" , "Flat-topped mountain" , "Geographical feature" , "Flat-topped hill with steep sides, common in the southwestern US" , "Flat tableland with steep sides" .)