Galdr
In old Germanic culture, a galdr, among other forms in old Germanic languages, refers to a spell or incantation; these were usually performed in combination with certain rites.
Etymology
and or wikt:galdor#Old English are derived from the reconstructed Proto-Germanic *galdraz, meaning a song or incantation. The terms are also related by the removal of an Indo-European -tro suffix to the verbs and, both derived from Proto-Germanic *galaną, meaning to sing or cast a spell. In Old High German the -stro suffix produced galster instead.The German forms were Old High German galstar and Middle High German (MGH) galster "song, enchantment", surviving in Modern German Galsterei and Galsterweib.
The Modern Scandinavian word for "crazy" is a derivative of the same root as galdr, and originally referred to someone whose mind has been distorted by a spell. Other related descendants of these words are,,, the latter component of English nightingale, related to ġiellan, the verb ancestral to Modern English yell, also cognate with Dutch gillen.
Attestations
Old Norse
Some incantations were composed in a special meter named galdralag. This meter was similar to the six-lined ljóðaháttr, also used for ritual, but added at least one more C-line. Diverse runic inscriptions suggest informal impromptu methods. Another characteristic is a performed parallelism, see the stanza from Skirnismál, below.A practical galdr for women was one that made childbirth easier, but they were also notably used for bringing madness onto another person, whence modern Swedish galen meaning "mad", derived from the verb gala. Moreover, a master of the craft was also said to be able to raise storms, make distant ships sink, make swords blunt, make armour soft and decide victory or defeat in battles. Examples of this can be found in Grógaldr and in Frithiof's Saga. In Grógaldr, Gróa chants nine galdrar to aid her son, and in Buslubœn, the schemes of king Ring of Östergötland are averted.
It is also mentioned in several of the poems in the Poetic Edda, and for instance in Hávamál, where Odin claims to know 18 galdrar. For instance, Odin mastered galdrar against fire, sword edges, arrows, fetters and storms, and he could conjure up the dead and speak to them. There are other references in Skírnismál, where Skirnir uses galdrar to force Gerðr to marry Freyr as exemplified by the following stanza:
A notable reference to the use of galdrar is the eddic poem Oddrúnargrátr, where Borgny could not give birth before Oddrún had chanted "biting galdrar" :
Old English
In Beowulf, ġealdru are used to protect the dragon's hoard that was buried in a barrow:Medieval tradition
During the Middle Ages, the term galdr often became synonymous with "witchcraft" and "magic" as a whole. In Old Swedish and Old Icelandic, a word for witch was "galdr woman".In Medieval Sweden, a drawn or written spell or incantation was called a "galdr letter". Such, intended to make the holder invulnerable, could be worn as an amulet and was called a "sword letter". This type of drawn spell was later banned.
There exist records from the 16th century of Icelandic Medieval magic sigils called "galdr staves", today commonly referred to as Icelandic magical staves in English.