Ecclesiastes 9:5

[Astreja]

"Memoria eorum" translates as "the memory of them" - in other words, others' memories of the deceased.  Very common on war memorials - the motto of the Royal Canadian Legion is "Memoriam Eorum Retinebimus," or "We will remember them" (retain the memory of them).

The passage essentially means that [others'] memories of the dead will eventually fade into nothingness.

Did you study Latin at a university? How old are you that you remember such details? Based on your profile picture, I'd guess you are at least 50.

I just turned 66, and I'm currently studying Latin in university (going into my second year of Latin, and my first year of Greek, in September). I have a very good memory for alphanumeric data (still remember the phone number my family had fifty years ago), and because I play in concert bands that sometimes rehearse or perform at Legions I regularly see monuments and plaques with the Legion slogan on it.