IPA: /kˈθoʊniən/
KK: /k'toʊniən/
Relating to the underworld or things that are beneath the earth.
In ancient mythology, chthonian deities were often associated with the earth and the afterlife.
Chthonian is derived from the Greek word "chthonios" (meaning of the earth or underground) which comes from "chthōn" (meaning earth or soil). The term refers to deities or spirits associated with the underworld or the earth.
Think of 'chthōn' meaning earth, and remember that 'chthonian' relates to beings or things that come from the earth or the underworld.