Where does “abyssalis” come from?

abyssalis (Latin) comes from Latin abyssus, from Ancient Greek ἄβυσσος, from Ancient Greek ἀ-, from Proto-Hellenic hə-, from Proto-Indo-European sm̥-, from Proto-Indo-European sem- — together, one.

abyssalis (Latin): Of, pertaining to or resembling an abyss;...

Definitions

Of, pertaining to or resembling an abyss;...

Ancestry of “abyssalis”, step by step

Step	Language	Word	Meaning
1	Latin	abyssus	an abyss
2	Ancient Greek	ἄβυσσος	bottomless, boundless; unfathomable; bottomless...
3	Ancient Greek	ἀ-	The alpha privativum, used to make words that...
4	Proto-Hellenic	hə-	same; together
5	Proto-Indo-European	sm̥-	one; with, together
6	Proto-Indo-European	sem-	together, one

Every word from Proto-Indo-European sem- →Every word from Ancient Greek ἀ- →Every word from Proto-Indo-European sm̥- →