This is the 12884th most frequent Portuguese word.
xingado
"Xingado" means "insulted" or "cursed at" in English.
Here, 'xingado' is used as a past participle to describe the state of the subject receiving insults from others.
Ele foi xingado pelo comportamento dele.
He was insulted for his behavior.
'Xingado' functions to show that the subject has experienced the action of being insulted prior to taking the decision.
Já xingado, ele decidiu sair da discussão.
Already being insulted, he decided to leave the discussion.
The use of 'xingados' indicates an action directed at the students, showing they were negatively addressed by their teacher.