See opinion in Webster's New World College Dictionary
noun
a belief not based on absolute certainty or positive knowledge but on what seems true, valid, or probable to one's own mind; judgment
an evaluation, impression, or estimation of the quality or worth of a person or thing
the formal judgment of an expert on a matter in which advice is sought
Law the formal statement by a judge, court referee, etc. of the law bearing on a case
See opinion in American Heritage Dictionary 4
(ə-pĭnˈyən)
noun
A belief or conclusion held with confidence but not substantiated by positive knowledge or proof: “The world is not run by thought, nor by imagination, but by opinion”(Elizabeth Drew).
A judgment based on special knowledge and given by an expert: a medical opinion.
A judgment or estimation of the merit of a person or thing: has a low opinion of braggarts.
The prevailing view: public opinion.
Law A formal statement by a court or other adjudicative body of the legal reasons and principles for the conclusions of the court.