Butterfly book, margin having rough notes (9)
I believe the answer is:
brimstone
'butterfly' is the definition.
(I've seen this before)
'book margin having rough notes' is the wordplay.
'book' becomes 'b' (abbreviation for book).
'margin' becomes 'rim' (both can mean something's edge).
'having' is a charade indicator (letters next to each other).
'rough' indicates an anagram (a rough or broken ordering of the letters).
'notes' anagrammed gives 'stone'.
'b'+'rim'+'stone'='BRIMSTONE'
(Other definitions for brimstone that I've seen before include "Yellow butterfly" , "Sulphur (when associated with hellfire)" , "Sulphur; butterfly" , "Old name for sulphur" , "Biblical sulphur that rained with fire on evil cities" .)