Roman writer or Roman leader in college embraced by Pope (9)
I believe the answer is:
petronius
'roman writer' is the definition.
'roman leader in college embraced by pope' is the wordplay.
'leader' suggests taking the first letters.
'in' is an insertion indicator.
'college' becomes 'eton' (I've seen this before).
'embraced by' means one lot of letters goes inside another.
'pope' becomes 'pius' (pope pius xii).
The initial letter of 'roman' is 'r'.
'r' going within 'eton' is 'etron'.
'etron' inserted into 'pius' is 'PETRONIUS'.
'or' is the link.
(Another definition for petronius that I've seen is " Roman author of Satyricon".)