superterraneous
/ˌsuːpətəˈreɪnɪəs/ /ˌsjuːpətəˈreɪnɪəs/Now rare
adjective
= superterranean.
Origin
Late 17th century; earliest use found in Philosophical Transactions of the Royal Society of London. From post-classical Latin superterraneus + -ous, after subterraneous.