Wiktionary
in memorium
adv. (misspelling of in memoriam English)
Wikipedia
In Memorium
In Memorium is a demo EP by British doom metal band Cathedral, released in 1990 through Rise Above. It was re-released in 1994 and was later re-released again in 1999 as 'In Memoriam', with additional live tracks from the 1991 the Netherlands and Belgium tours.
Usage examples of "in memorium".
She was preserving it, a sign on the gate said, in memorium to her dear departed spouse.
In that week I purchased a tiny glazed Hikhoff from a student sculptor who made it in memorium.