"Idis" originally seems to have meant "atheling-woman". There is considerable doubt as to whether it is actually the same word as the Old Norse dís; the loss of the initial vowel is impossible to account for, but since the use is so similar, those who prefer English or general Germanic terms use "idis" instead of the Old Norse word.
In the singular, the word itself is very general in meaning. Both "idis" (or Anglo-Saxon "ides") and dís are applied to human women, womanly ghosts, goddesses, and figures such as Grendel's mother and Hel; in skaldic kennings, someone's dís is their kinswoman, whether living or dead. As a name-element, this word was very common, especially in Old Norse (Freydís, Ásdís, Þórdís, Hjördís, and the very rare Óðindís) but also on the Continent (Agedisus, Disibod, Tiso). The walkurjas are described as "Herjans dísir" (Óðinn's idises - Guðrúnarkviða I) as well as "Herjans nönnur" (Óðinn's women - Völuspá 30).
Although the plural term is most often used specifically for the dead women of the clan who still guard their descendants and help them in various ways, it can also speak of living women; the two have basically the same might, though the dead ones, dwelling wholly in the hidden realms, are thought of as stronger in matters of magic. The Old High German "Erste Merseburger Zauberspruch" gives us a clear picture of one of the things they do:
"Once the idises sat, sat here and there.
Some fastened fetters, some loosened fetters,
some plucked at chains;
spring the chains free! the fighters come out."
In Wealtheow and the Valkyrie Tradition, Damico tried very hard to prove that this might of fettering and loosing characterized a number of Germanic women as valkyries, and ended up showing either that it was a typical power of Germanic women, or that all mighty Northern females, including christian heroines such as Juliana, had originally been valkyries.
The idises also take part in battle in other ways. The women of the Helgi lays, Sváva and Sigrún (who are probably of the special type called "spae-idis" - see "Soul, Death, and Rebirth"), ride over air and water to ward their beloved Helgis in war. In Helgakviða Hundingsbana I, Helgi sees Sigrún and her troop of "southern dísir" in bloody byrnies with flashing lances after his battle with Hunding's sons; she also wards his fleet through a storm so that they come safely into the harbour. Helgakviða Hjörvarðssonar tells how Sváva is Helgi's unseen protector when the troll-woman Hrimgerðr attacks his ship, and also shows the troop of idises as bringers of fruitfulness: "(Their) steeds whinnied; from their manes fell dew in deep dales, hail in high woods, and thence comes good harvest to men." The battle-aspects of these women have often been taken as support for the prose identification of them as walkurjas. However, Germanic women typically went to the battlelines to encourage their men, and it is very likely that those who were skilled in magic also helped their beloveds in that way, faring forth to do battle unseen above the heads of the warriors. This seems to be more a trait of Teutonic womanhood in general than something specifically associated with the cult of Wodan, as the walkurja certainly is. As seen below in the story of Þiðrandi, family idises also appear as mounted warriors, even being mighty enough to slay men in the Middle-Garth.
Two of the greatest clan-idises were Þórgerðr and Irpa, idises of the Jarls of Hlaðir, who had their own statues "as big as a man with gold ring on arm and head-dress on head" (Njáls saga ch. 88), the fulltruar (fully-trusted; that is, patron deities of) the Jarl Hákon. In his battle against the Jómsvíkings, Hákon made a sacrifice to these goddesses, whereupon a sudden storm came out of the north, in which Þórgerðr and Yrpa appeared with arrows flying out of their fingertips; and this was the chief decisive factor in the battle. Þórgerðr's statue, together with that of Freyr's, was singled out for special abuse by Óláfr Tryggvason when he came to destroy the hof at Trondheim.
The idises help in birthing: Sigrdrífa counsels Sigurðr, as part of a midwife's skills, to "bid the idises aid". They are quite likely to be the wights that Snorri describes in his Edda as the norns who come to every child when it is born to speak its doom - "some of the ætt of Ases, some of the ætt of alfs, some are daughters of Dvalinn (dwarves)". He adds that "Good norns of fine kin shape good lives; but those folk who have ill-shaping, that is ruled by ill norns". This seems to be closely tied to the belief in the luck of the clan, which the idises may perhaps have been seen as passing to the child at birth (or name-giving):
Unlike walkurjas, idises were widely worshipped. It is likely that, as with the alfs, the belief in the clan-mothers goes back to the eldest times. However, the oldest surviving examples we have of a cult specifically dealing with the "Mothers" comes from the Roman occupation of the western banks of the Rhine. There are a number of little clay figures and stone votive sculptures showing three women with (usually) crescent head-dresses and baskets of fruit, cornucopiae, or suckling children sitting in a row. All of these bear inscriptions identifying them as the "Matronen". Many of the "Matronen" inscriptions are identified by tribe: "Suebian Mothers", "Germanic Mothers", "paternal Frisian Mothers"; others' names show them to be warders or gift-givers (Simek, Dictionary, pp. 204-08).
In Ynglinga saga and Heiðreks saga, a dísarsalr (idis' hall) is spoken of. It is a place for sacrifice of various sorts. The king Aðils falls off his horse and dies in the idis' hall, and one of Heiðrekr's wives hangs herself there. The death of Aðils is especially interesting, as it is attributed to a witch; it is possible that, as with the story of Þiðrandi (discussed below), the attendant idis chose her own sacrifice.
As well as being protectors, idises also come to claim their kin when it is time for the living to die. Before Gunnarr begins his ill-fated faring to the hall of the Huns, his wife dreams that "Dead women came hence in the night; they were mourning-clad, and wished to choose thee, bidding you swiftly to their benches...they were your dísir" ("Atlamál in groenlenzco" 28).
The best-known story of the idises is that from Kristni þáttr in Óláfs saga Tryggvasonar (Flateyjarbók). At a certain Winternights feast, a man called Þórhallr had an ill boding that someone should die that night, and said that no one should go out. But when most folk were asleep there was a knock at the door. Þiðrandi "took sword in hand and went out. He saw no one....he went then under the woodpile and heard riders galloping from the north. He saw that there were nine women and they were all in black clothes and had drawn swords in their hands. He also heard riders galloping from the south; they were also nine women all in light clothes on white horses. Then Þiðrandi wanted to turn inside and tell folk of it. Then the black-clad women came forward and attacked him, but he warded himself well and manfully. Some time afterward þórhallr woke up and asked if Þiðrandi was awake, and he was not answered. Þórhallr said, "Then you must have over-slept." Then they went out. There was moonshine and frost-weather. They found Þiðrandi lying wounded and he was borne in. And whem folk had words with him he said all that had happened. He died at dawn that same morning and was laid in a howe according to the old custom of Heathen folk". Þórhallr then interprets the events as meaning that a new custom should come to the land, and says, "I expect that your dísir which have followed this old faith have now learned of this changing of customs and that they shall be forsaken by their kin. Now they must not want to have no share from you before they part from you and they must have (taken) this as their part. But the better dísir must have wanted to help him and were not able to do so as things stood."
Like Þiðrandi, Gísli Súrsson (Gísli the Outlaw) had two draumkonur (dream-women) who came to him, the better one giving him advice and the other one threatening. Shortly before his death, he dreamed that the second one came and washed him in blood; and after that he had such a fear of the dark that he could not dare to be alone. Again, the author of the saga gave the tale a slightly christian slant, but the basic belief in a bright idis helping and guarding and a dark idis calling towards death is probably heathen in origin. Part of Óðinn's doom-speech, as he reveals himself to Geirroðr at the end of Grímnismál, is "(your) dísir are foelike - now you shall see Óðinn!" (that is, die). In Reginsmál, the god counsels his hero Sigurðr, "That is very dangerous if your foot drops (if you stumble) when you go to do battle. Betraying dísir stand at your two sides and wish to see you wounded." In his extensive bracteate studies, Karl Hauck has interpreted some of the animal figures, especially the bird-headed snake-monsters that appear to be threatening a rider on Tulstrup-C and Dannau-C, as showing just such ill-willing idises ("Fünens besonderer Anteil", pp. 120-27), which he sees as causing Balder's horse to stumble and be wounded as may be described in the Second Merseburger Charm (see "Balder").
Chiefly, however, the idises are helpful to their kin. Little is shown of their actual workings, except for one saga in which the family idis afflicts a kinsman with various illnesses to keep him from walking into an ambush that would otherwise have been fatal. We thus know that they have foresight (the word spádísir is used in Völsunga saga to describe Sigmundr's battle-protectresses in his final fight); to those who can hear them, they give warnings or advice. The special association of their worship with Winternights (mentioned in Víga-Glúms saga and Heiðreks saga) suggests that they are also goddesses of fruitfulness, probably in regards both to humans and their lands and cattle.
As well as having their own halls or hofs, the idises also had holy stones in which they dwelt. The Norwegian Disahrøys (stone-pile of the dísir) suggests that harrows of rocks were built to these wights. This is very like the "harrow...of heaped stones" (Hyndluljóð 10) which Óttarr, who "trusted ever...in the ásynjur" built for Freyja; though such harrows were probably not exclusive to womanly wights, they do seem to have been thought very fitting.
The Frowe is called "Vanadís", idis of the Wans. This has often been taken to show that she is the leader of the idises or the great idis, but given the general usage of the word to mean "kinswoman", this reading is probably excessive. However, as Fro Ing is the lord of Alf-Home, and it is likely that the idises and alfs are womanly and manly clan-ghosts of the same sort, it seems clear that his sister should have a similar tie with the idises, and be called on when they are called, as is the usual custom of the true today.
Together with the Frowe/Fro-idis/alf pairings, there is also reason to think of a Frija/Wodan-idis/alf connection. The reference to Óðinn as being the god who will be angered by a christian at the álfablót in Sigvatr's Austrafaravísur, as discussed under "Alfs", suggests strongly that he has a part in the cult of those wights as well. As the realm of the dead, especially the ancestors and the mound-dead, is the area in which Wodan and Fro Ing overlap most and work most closely together, this is hardly surprising. Frija and her goddesses could also be called "the idises"; the motherly character of the dísir, especially when the cult of the Matronen is thought on, seems to bring them at least as much into Frija's realm as the Frowe's.
In A Book of Troth, Thorsson offers a "Blessing of the Dises" in which several of the different women's personal names with the "dís" element are used in a call to the idises (p. 168). Here we offer a short list from which folk can put together such a call. Those slightly familiar with Old Norse can also easily generate their own idis-names/descriptions; such created forms have been marked with an * here.
idis of children
Freyr's idis or Freyja's idis (forms would have been identical in ON)
horse-idis (note: used for Hel)
Óðinn's idis (only found twice, on late Swedish runestones -- may have been a cultic title, but more likely formed after the other god-idis compounds)
prophecy-idis (used as a descriptive rather than personal name)
idis of the Wans (the Frowe)