The Erinyes, also known as the Eumenides, are chthonic goddesses of vengeance in ancient Greek religion and mythology. A formulaic oath in the Iliad invokes them as "the Erinyes, that under earth take vengeance on men, whosoever hath sworn a false oath". Walter Burkert suggests that they are "an embodiment of the act of self-cursing contained in the oath". They correspond to the Dirae in Roman mythology. The Roman writer Maurus Servius Honoratus wrote that they are called "Eumenides" in hell, "Furiae" on Earth, and "Dirae" in heaven. Erinyes are akin to some other Greek deities, called Poenai.

The word chthonic, or chthonian, is derived from the Ancient Greek word χθών, "khthon", meaning earth or soil. It translates more directly from χθόνιος or "in, under, or beneath the earth" which can be differentiated from Γῆ, or "ge", which speaks to the living surface of land on the earth. In Greek, chthonic is a descriptive word for things relating to the underworld and can be used in the context of chthonic gods, chthonic rituals, chthonic cults, and more. This is as compared to the more commonly referred-to Olympic gods and their associated rites and cults. Olympic gods are understood to reference that which exists above the earth, particularly in the sky. Gods that are related to agriculture are also considered to have chthonic associations as planting and growing take place in part under the earth.