It is a verb.
Meaning : to express an opinion.
Synonyms : suggest, submit, advance, propose, venture, volunteer, put forward, moot, air, posit, propound, say
Etymology: Middle French "opiner", from Latin "opinari" meaning " to have an opinion"
1)Most doctors opine that physical exercise and a wholesome diet can prevent people from falling prey to stress related ailments.
2)He opined that it was all a sad mistake.
3)He opined that he needed more money to perform this task.
4)She opined that this is not the right moment to question the authorities.