Etymology unknown. Potentially “devourer” or “of the spoils”, or “widespreading" $^{91}$
The Laphria Festival was a celebration held most likely in honour of Artemis, though the epithet can also be attached to Apollon, Hermes, Athena, and Britomartis. As an epithet of Artemis, it is strongly connected to her hunting domain. The festival took place between the 9th of Bysios and the 7th of Theoxenios.
The 6th of Theoxenios has been chosen, as the 6th is a sacred day of Artemis, and the last possible date for this festival (which is scheduled to occur before the Theoxenia on the 7th). This is one of a series of 3 festivals for Artemis, all held within a month of each other, indicating that this was an important time of year for Artemis in Delphi.
There are traces of ritual performances for the goddess Laphria in various regions, including Western Lokris, Delphi and Phokis, Doris, Messenia, and Elis. The name "Laphria" is of unknown etymology but could mean "devourer," "of the spoils," or "widespreading.” It’s an epithet frequently associated with the spoils of war.
According to Pausanias, the people of Patrai celebrate a festival of Artemis Laphria with a unique sacrificial method. The festival involves a procession, with the priestess riding in a chariot yoked to deer. Sacrifices include live birds and various animals like wild boars, deer, gazelles, and even wolf and bear cubs. Fruits from cultivated trees are also placed on the altar. The festival culminates in setting fire to a circle of green logs, and despite some animals escaping the flames, they are brought back to the pyre.
This is, however, talked about as a unique celebration, so its unclear how much - if any - of these details applied to the Delphic festival.
[...] there are traces of ritual performances for the goddess Laphria mainly in the regions incorporated in the Aitolian koinon or politically linked to it: Western Lokris, Delphi and Phokis, Doris, Messenia, and Elis.
– Claudia Antonetti, Ethnos & Koinon $^{90}$
Artemis also receives a good amount of timai under three different dedications corresponding to the feasts named Eucleia, Artamitia, and Laphria
Lines D7-8: A series of three festivals of Artemis are mentioned here: Eukleia, Artamitia and Laphria (see again Rougemont, p. 59, with refs.). For Eukleia, a common epithet for the goddess, see possibly here CGRN 107 (Kalaureia), lines 1-10. Note however that the Laphria are not necessarily tied to Artemis: Laphrios is notably found as an epithet of Apollo, e.g. Str. 10.2.21 and IG IX.1² 149 (Kalydon). Given the chronological sequence of the list in these lines, these must have fallen after 9 Bysios, either in that month, or during the following month of Theoxenios (this corresponded roughly to Athenian Anthesterion-Elaphebolion).
– A Collection of Greek Ritual Norms (CGRN) – Two excerpts from the dossier of regulations of the Labyadai at Delphi $^{5}$
{7.18.8} On the acropolis of Patraiis a sanctuary of Artemis Laphria. The surname of the goddess is a foreign one, and her image too was brought in from elsewhere. For after Calydon with the rest of Aetolia had been laid waste by the Emperor Augustus in order that the Aetolian people might be incorporated into Nikopolis above Actium, the people of Patraithus secured the image of Laphria.
{7.18.9} Most of the images out of Aetolia and from Acarnania were brought by Augustus’ orders to Nikopolis, but to Patraihe gave, with other spoils from Calydon, the image of Laphria, which even in my time was still worshipped on the acropolis of Patrae. It is said that the goddess was surnamed Laphria after a man of Phokis, because the ancient image of Artemis was set up at Calydon by Laphrios, the son of Kastalios, the son of Delphos.
{7.18.10} Others say that the wrath of Artemis against Oineus weighed as time went on more lightly (elaphroteron)on the Calydonians, and they believe that this was why the goddess received her surname. The image represents her in the guise of a huntress; it is made of ivory and gold, and the artists were Menaechmus and Soldas of Naupaktos, who, it is inferred, lived not much later than Kanakhos of Sikyon and Kallon of Aegina.
{7.18.11} Every year too the people of Patraicelebrate the festival Laphria in honor of their Artemis, and at it they employ a method of sacrifice peculiar to the place. Round the altar in a circle they set up logs of wood still green, each of them sixteen cubits long. On the altar within the circle is placed the driest of their wood. Just before the time of the festival they construct a smooth ascent to the altar, piling earth upon the altar steps.
{7.18.12} The festival begins with a most splendid procession in honor of Artemis, and the girl officiating as priestess rides last in the procession upon a car yoked to deer. It is, however, not till the next day that the sacrifice is offered, and the festival is not only a state function but also quite a popular general holiday. For the people throw alive upon the altar edible birds and every kind of victim as well; there are wild boars, deer and gazelles; some bring wolf-cubs or bear-cubs, others the full-grown beasts. They also place upon the altar fruit of cultivated trees.
{7.18.13} Next they set fire to the wood. At this point I have seen some of the beasts, including a bear, forcing their way outside at the first rush of the flames, some of them actually escaping by their strength. But those who threw them in drag them back again to the pyre. It is not remembered that anybody has ever been wounded by the beasts.
– Pausanias