dictum

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An authoritative, often formal pronouncement.
• noun Law A side remark made in a judicial opinion that is not necessary for the decision in the case and therefore is not to be regarded as establishing the law of the case or setting legal precedent.

from The Century Dictionary.

• noun A positive or judicial assertion; an authoritative saying.
• noun In law, an opinion of a judge which does not embody the resolution or determination of the court, and is made without argument, or full consideration of the point, and is not the professed deliberate determination of the judge himself.
• noun In logic, that part of a modal proposition which consists of the proposition to which the modality is applied.
• noun Synonyms Aphorism, Axiom, Maxim, etc. See aphorism.

from the GNU version of the Collaborative International Dictionary of English.

• noun An authoritative statement; a dogmatic saying; an apothegm.
• noun A judicial opinion expressed by judges on points that do not necessarily arise in the case, and are not involved in it.
• noun (French Law) The report of a judgment made by one of the judges who has given it.
• noun An arbitrament or award.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An authoritative statement; a dogmatic saying; a maxim, an apothegm.
• noun A judicial opinion expressed by judges on points that do not necessarily arise in the case, and are not involved in it.
• noun The report of a judgment made by one of the judges who has given it.
• noun An arbitrament or award.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an authoritative declaration
• noun an opinion voiced by a judge on a point of law not directly bearing on the case in question and therefore not binding