Which would be the best word for "abyss" in classical Latin?

Question

In Nietzsche's Beyond Good and Evil, he has the following well-known line:

Wer mit Ungeheuern kämpft, mag zusehn, dass er nicht dabei zum Ungeheuer wird. Und wenn du lange in einen Abgrund blickst, blickt der Abgrund auch in dich hinein.

Whoever battles monsters should see to it that in the process he does not become a monster himself. And when you look long into the abyss, the abyss also looks into you.

Original text and translation from this post.

What would be the best word for abyss in this usage? My initial thoughts for words used in the classical period were barathrum, chasma, or profundum. I'm not opposed to later words like abyssus, but I prefer classical when possible. Does one of the former three best capture abyss in the way that Nietzsche meant?

Answer 1

Here is what Georges has to say about "Abgrund" (translation of the non-Latin parts by the humble undersigned):

I) lit.: infinita or immensa altitudo (an enormous depth). – terrae hiatus, in context simply hiatus (cleft). – locus praeceps or declivis et praeceps (sudden precipice). – locus praeruptus (steep precipice). – vorago (a gorge). – gurges (an eddy [you may like to know the German word here was "Strudel"]). – profundum with or without maris (the deep of the sea)

It further gives some translations for the tropic meaning of "Abgrund," which differ perhaps somewhat from "abyss" and in any event, in my opinion, are not helpful in our case.

I like altitudo, but I think it is too ambiguous. I would therefore go with vorago:

Caveat, qui pugnat cum monstris, ne ipse fiat monstrum. Etenim si diu voraginem intuitus eris, etiam vorago te intuebitur.

Ille severus Conardus quidem, ad quem nexum dedisti, fortasse me vituperaret propter verbum etenim, quia causalitatem quandam indicare videtur.

Answer 2

My suggestion is gurges, gurgitis (m.):

I. raging abyss, whirlpool, gulf
II.A. In gen., waters, stream, sea
II.B Of insatiable craving, an abyss; of persons, a spendthrift, prodigal

I find the collection of translations and tones more appropriate than those of other close hits: gula, barathrum, chasma, profundum. These are not bad options either, and the best choice depends on the tone you want (are the depths raging or dark?) and possible conflicts with other words (is something else profundus?).