Where does “subterraneously” come from?

subterraneously (English) comes from English subterraneous, from Latin subterraneus, from Latin sub-, from Proto-Indo-European upó, from Proto-Indo-European h₃ewp-.

subterraneously (English): In a subterraneous manner; underground

Definitions

In a subterraneous manner; underground

Ancestry of “subterraneously”, step by step

Step	Language	Word	Meaning
1	English	subterraneous	Subterranean
2	Latin	subterraneus	underground, subterranean
3	Latin	sub-	sub-
4	Proto-Indo-European	upó	under, below
5	Proto-Indo-European	h₃ewp-	—

Every word from Proto-Indo-European h₃ewp- →

subterraneously — Etymology, Origin & Word History | Etymology Explorer