Chthonic, apart from its literal translation meaning 'subterranean', its historical or interpretive definition designates, or pertains to, deities or spirits of the underworld, especially in relation to Greek religion. The Greek word khthon is one of several for "earth"; it typically refers to the interior of the soil, rather than the living surface of the land or the land as territory. It evokes at once abundance and the grave.
Some dictionaries, such as the OED, state that the first two letters should be pronounced, while others, such as the AHD, record these letters as silent. The modern pronunciation of the Greek word "χθόνιος" is, although the Classical Greek pronunciation would have been.