A Scottish historian is clearly wrong (7)
I believe the answer is:
carlyle
'a scottish historian' is the definition.
(I've seen this in another clue)
'clearly wrong' is the wordplay.
'wrong' indicates an anagram.
'clearly' with letters rearranged gives 'CARLYLE'.
'is' acts as a link.
(Other definitions for carlyle that I've seen before include "Victorian historian" , "Scots historian" , "Thomas -, nineteenth century British essayist/historian" , "Thomas --, Scottish social historian" , "Thomas -, Sc. essayist" .)