Words connected with seidr indicate signs, soothsaying, sorcery, rope and binding …
This is interesting because the etymology of the word seiðr would have it derive from Proto-IE *soito, which means rope, cord or string and is derived from the root meaning/word to bind. The Proto-Celtic word *soito is the root of the modern Welsh, Cornish and Breton words hud, hus, and hud respectively (s -> h). However, this doesn’t seem to have given us a cognate word in Gaelic. Nevertheless, the idea of magic and fate being connected to threads was indeed found in folk tradition right up to the present day, and in mythology. It is also interesting to note that there seems to be some separation of the words dealing with magic and the words connected to druidry in the Brythonic languages, yet in the Gaelic languages the words for magic seem to be connected to druidry. Was an old(er) word perhaps lost?
In Norse tradition, Óðinn was a powerful seiðr figure, but seiðr it was Freyja, of the Vanir, who had the knowledge of seiðr and taught it to others. Another interesting thing about seiðr was how it was viewed in Norse culture with a mixture of fear and suspicion, so it must have held a very powerful hold in the minds of the people. It also seems to have been passed from female to male, something with which we see parallels in traditions – supposedly unrelated – found in the West Country (in traditional folklore, magic had to be learned from someone of the opposite sex, male to female or female to male).