1. The view someone takes about an issue; especially, when it is based solely on personal judgment: "In my opinion, the study of vocabulary is essential to a superior education."
2. A view regarding the worth of someone or something: "For some reason, they don't seem to have a very good opinion of what I am striving to accomplish."
3. An expert assessment of something: "She told the dentist that she wanted a second opinion before he started to pull out so many teeth."
4. The view or views held by most people or by a large number of people: "Political polls are used to establish trends and other political opinions."
5. A belief or conclusion held with confidence but not substantiated by positive knowledge or proof.
6. In law, a conclusion drawn from the observation of the facts.

1 A brief opinion of a court that announces the result of a case without any detailed discussion and which is usually unpublished and cannot be cited as a precedent.
2 An opinion of the U.S. Tax Court that is ordered not to be published but which is authoritative as a precedent,
3. An opinion of a judicial court that sets forth the court's views or intended decision in a case but does not constitute a final judgment.

Knowing what people are undecided about.

Nonsensus of opinion.