Dogmatic

/dɒɡˈmæt.ɪk/ adjective easy

Stating opinions as if they were unquestionably true, without allowing for debate.

The professor's dogmatic insistence that there was only one correct interpretation frustrated students who wanted to debate.

Memory Trick

The word comes from 'dogma,' a fixed system of belief — a dogmatic person treats their own opinion like unquestionable dogma, closed to debate.