"statement in passing," a judge's expression of opinion not regarded as binding or decisive, Latin, literally "something said incidentally;" from obiter "by the way" + dictum in the legal sense "a judge's expression of opinion which is not the formal resolution of a case or determination of the court."
Obiter dicta, legal dicta ... uttered by the way (obiter), not upon the point or question pending, as if turning aside for the time from the main topic of the case to collateral subjects. [Century Dictionary]
Latin obiter is from ob "in front of, toward" (see ob-) + iter "journey" (from PIE root *ei- "to go"). Klein's sources, however, say it is ob with the suffix -iter on analogy of circiter "about" from circa. Also see obituary.
"day on which a memorial is made," by 1819, of any anniversary date, especially a religious anniversary; see memorial (adj.). As a specific end-of-May holiday commemorating U.S. war dead, it began informally in the late 1860s and originally commemorated the Northern soldiers killed in the Civil War. It was officially so called by 1869 among veterans' organizations, but Decoration Day also was used. The Grand Army of the Republic, the main veterans' organization in the North, officially designated it Memorial Day by resolution in 1882:
That the Commander-in-Chief be requested to issue a General Order calling the attention of the officers and members of the Grand Army of the Republic, and of the people at large, to the fact that the proper designation of May 30th is Memorial Day and to request that it may be always so called. [Grand Army Blue Book, Philadelphia, 1884]
The South, however, had its own Confederate Memorial Day, and there was some grumbling about the apparent appropriation of the name.
The word "Memorial" was adopted by the Maryland Confederates shortly after the war, and has been generally used throughout the South. It is distinctively Confederate in its origin and use, and I would suggest to all Confederate societies to adhere to it. The Federals' annual day of observance is known as "Decoration Day," having been made so by an act of Congress, and the 30th day of May named as the date. In Maryland there is annually a Decoration Day and a Memorial Day. The two words are expressive not only of the nature of the observance, but also of the people who participate therein. [Confederate Veteran, November 1893]