President has fat philosopher castrated (7)
I believe the answer is:
abelard
'philosopher castrated' is the definition.
I can't judge whether this definition defines the answer.
'president has fat' is the wordplay.
'president' becomes 'Abe' (Abraham (Abe) Lincoln).
'has' means one lot of letters go next to another.
'fat' becomes 'lard' (lard is a kind of fat).
'abe'+'lard'='ABELARD'
Can you help me to learn more?
(Other definitions for abelard that I've seen before include "theologian in France" , "12th century monk" , "He loved Heloise" , "French cleric" , "Monk who had tragic affair with Heloise" .)