The English noun abyss, meaning generally “a bottomless or immeasurably deep gulf or great space” and figuratively “anything that seems to be endless, insuperable, or unfathomable,” is a descendant of the classical Greek adjective ábyssos, which meant “bottomless” and was itself a compound formed from the Greek prefix a-, meaning “not,” and the Greek noun bussós, meaning “bottom.” The Greek passed into Late Latin as abyssus, a noun that was commonly used to mean “immeasurably deep pit,” and this later passed into Old French as the noun abisme. (The m appears in the Old French due to the influence of the Vulgar Latin abysmus, a plebeian variant of the aforementioned Late Latin noun.) In the thirteenth century, some English speakers were influenced directly by the Latin word and some by the Old French, the result being that there were initially three forms of the English noun: abissus, abime, and abysm. Abissus and abime both died out during the sixteenth century and were supplanted by the contemporary abyss, but abysm remained in common use until the early seventeenth century and persists even today in literary and poetic application.
©2016 Michael R. Gates