Disdained to take notes on treatment for corns (7)
I believe the answer is:
scorned
'disdained' is the definition.
('scorn' can be a synonym of 'disdain')
'notes on treatment for corns' is the wordplay.
'notes' becomes 'ed' (**).
'on' means one lot of letters go next to another.
'treatment for' is an anagram indicator (I've seen this in other clues).
'corns' with letters rearranged gives 'scorn'.
'ed' after 'scorn' is 'SCORNED'.
'to take' is the link.
(Other definitions for scorned that I've seen before include "''Hell hath no fury like a woman .. . . . . .''" , "Derided" , "Dismissed" , "Treated with contempt" .)