Shouted at bad grade (5)
I believe the answer is:
raged
'shouted' is the definition.
The answer and definition can be both to do with communicating as well as being past participle verbs.
Perhaps there's a link between them I don't understand?
'bad grade' is the wordplay.
'bad' is an anagram indicator.
'grade' anagrammed gives 'RAGED'.
'at' is the link.
Can you help me to learn more?
(Other definitions for raged that I've seen before include "expressed vitriol?" , "was having fits" , "Spoke violently" , "Flipped one's lid" , "Behaved violently" .)