1. a personal belief or judgment that is not founded on proof or certainty;
"my opinion differs from yours"
"what are your thoughts on Haiti?"
2. a belief or sentiment shared by most people; the voice of the people;
"he asked for a poll of public opinion"
3. a message expressing a belief about something; the expression of a belief that is held with confidence but not substantiated by positive knowledge or proof;
"his opinions appeared frequently on the editorial page"
4. the legal document stating the reasons for a judicial decision;
"opinions are usually written by a single judge"
5. the reason for a court's judgment (as opposed to the decision itself)
6. a vague idea in which some confidence is placed;