abyss comes from Late Latin abyssus, from Ancient Greek ábyssos ('bottomless'), from a- (privative 'without') + byssós ('depth, bottom'). Morphologically, the word is transparent as a compound: its parts remain visible in the modern spelling, while the older history of those parts supplies the deeper ancestry. In modern use, the noun sense is "a deep or seemingly bottomless chasm", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as abysm and derivatives such as abyssal, abysmal, showing how the same base continues to support neighboring English vocabulary. The principal historical forms in the chain include Late Latin abyssus, Ancient Greek ábyssos, which anchor the explanation in named linguistic material.