Strain with note, horribly loud (10)
I believe the answer is:
stentorian
'loud' is the definition.
('stentorian' can be similar in meaning to 'loud')
'strain with note horribly' is the wordplay.
'with' is a charade indicator (letters next to each other).
'horribly' indicates an anagram.
'strain' after 'note' is 'notestrain'.
'notestrain' is an anagram of 'STENTORIAN'.
(Other definitions for stentorian that I've seen before include "(Of a person's voice) loud and powerful" , "Strident" , "booming" .)