Law. an incidental or supplementary opinion by a judge in deciding a case, upon a matter not essential to the decision, and therefore not binding as precedent.
Origin
1805-15; < Latin: (a) saying by the way
British Dictionary definitions for obiter dictum
obiter dictum
/ˈɒbɪtə ˈdɪktəm; ˈəʊ-/
noun (pl) obiter dicta (ˈdɪktə)
1.
(law) an observation by a judge on some point of law not directly in issue in the case before him and thus neither requiring his decision nor serving as a precedent, but nevertheless of persuasive authority
2.
any comment, remark, or observation made in passing
Word Origin
Latin: something said in passing
Word Origin and History for obiter dictum
"statement in passing," a judge's expression of opinion not regarded as binding or decisive, Latin, literally "something said incidentally;" see obiter + dictum.