He is a well-known opiner in the field of politics.

The opiners disagreed on the best course of action.

The opinators disagreed on the best course of action.

She spoke opinatively about the new movie.

The movie's ending was opinable, leaving the audience with different interpretations.

The opinant shared their thoughts on the matter during the meeting.

The opinings of the committee members varied greatly.

The opinants disagreed on the best course of action.