Self-opinionated

прилагательное 1) самоуверенный, самонадеянный Синоним(ы): conceited, arrogant, self-confident, self-assured 2) упрямый

Большой англо-русский словарь

Self-opinionated

adjective 1. conceited 2. stubbornly holding to one's own opinion; opinionatedself-opinionatedness noun

Merriam-Webster's Collegiate Dictionary