Roman historian found in a cat-suit (7)
I believe the answer is:
tacitus
'roman historian' is the definition.
(I know that Tacitus is a historian)
'found in a cat-suit' is the wordplay.
'found in' is an anagram indicator.
'cat'+'suit'='catsuit'
'catsuit' with letters rearranged gives 'TACITUS'.
(Other definitions for tacitus that I've seen before include "Writer" , "Old history master" , "Roman historian, annalist" , "Roman politician and historian" , "Old historian" .)