self-opinionated
US /ˌself.əˈpɪn.jə.neɪ.tɪd/
UK /ˌself.əˈpɪn.jə.neɪ.tɪd/

1.
presuntuoso, dogmatico, testardo
having a high opinion of oneself or one's own opinions; conceited or dogmatic
:
•
His self-opinionated remarks often alienated his colleagues.
Le sue osservazioni presuntuose spesso allontanavano i suoi colleghi.
•
She was too self-opinionated to consider other viewpoints.
Era troppo presuntuosa per considerare altri punti di vista.