ˈthänik adjective
or chtho·ni·an ˈthōnēən
Etymology: chthonic from Greek chthon-, chthōn earth + English -ic; chthonian from Greek chthoni os in or under the earth (from chthon-, chthōn ) + English -an — more at humble
1. of a divinity or a spirit : dwelling or reigning in the underworld : infernal
Pluto was the chthonic counterpart of Zeus
2. : relating to infernal deities or spirits : ghostly
chthonic worship