In question board, DovahKiinZaan suggested a translation for "Black Book". the Black Book is a hoard item.

These books contain an immense power. Since there is a translation for Elder Scrolls, DovahKiinZaan rightly thought that there should be a translation for "Black book".

Literally translating, "Black Book" is "suleyk mindah", however I would suggest something like "power knowledge", or "suleyk mindah".

The Elder Scrolls features quite a few sources of "powerful knowledge," so I'm not sure something like suleyk-mindah would be descriptive or specific enough to be a word for the Black Books.

Some other ideas:

• Vel, from ved "black" and kel "Elder Scroll" (vel is already a word but it's non-canon, I'd consider changing it)
• Vokel, kel with the prefix vo-, not the most lore-accurate representation of the Black Books but kind of poetic
• Vedrot "black word" / Vulrot "dark word" / Vonunrot "unseen word"
• Vedmindah or Vedmindok "black knowledge" / Vulmindah or Vulmindok "dark knowledge"
• Vonunrot "unseen word"
• Vulmiin "dark eye," miin referring to Mora himself

The word is nowvulmindok, or dark knowledge

I think that vel and vulmiin sound the best, vel because it is short yet effective, and vulmiin because it is a referrence to Mora himself.