(Featured image: Close-up of the Franks Casket likely depicting the Norns)
Old English wyrd—whether decreed by pagan forces or by the Christian God—generally has the meaning ‘fate, destiny.’ It literally means ‘that which becomes, happens’ and reflects Germanic *wurdiz, related to the verb weorþan ‘turn, become.’ (The þ-d alternation is due to Verner’s law.)
Anglo-Saxon poetry is full of gnomic pronouncements about wyrd, such as this famous one, which closes the introductory lament of The Wanderer:
ƿyrd bið ful aræd
Fate is entirely set in its ways! (l. 5b)
The underlying PIE root is *wert- ‘turn,’ and the verb weorþan has such Indo-European cognates as Latin verto ’cause to turn’ (its passive participle versus ‘turned [towards]’) and Sanskrit vartate ‘turns, is turned.’
Germanic cognates of wyrd ‘fate’ are abundant in older languages. The Old High German Hildebrandslied offers the gem wēwurt skihit—
ƿelaga nu ƿaltant got quad hiltibrant ƿeƿurt ſkihit
“Well now, Almighty God,” quoth Hildebrant, “misfortune occurs!” (ll. 48–49)
—in which wē-wurt is literally “woe-weird” or “sorrowful-fate.” (Skihit is modern German geschehen ‘happen.’) Thus the phrase is essentially an Old High German “shit happens.”
In North Germanic, *wurdiz ‘fate’ becomes Urðr, one of the mythological Norns, the three sisters who spin the threads of fate for mortals and gods alike. Urðr, who comes to have the past as her realm (where urðr signifies ‘that which has [already] happened’), is accompanied by Verðandi (lit. ‘that which is happening’; from the same root as urðr) who governs the present, and Skuld (lit. ‘that which must happen’) whose domain is the future.
This historical sense of wyrd—’fate, destiny’—is gradually lost in the centuries following the Old English period. In early Modern English, the word survives in the fossilized expression weird sisters—that is, “fate sisters”—a name for three legendary witches evocative of the Norns of mythology.
The Shakespearean weird sisters in a Doctor Who episode
It is in fact William Shakespeare’s use of the term weird sisters in Macbeth that breathed new life into the word. (Wayward sisters, another name for these witches, may be a folk etymology of weird sisters by a population that was unfamiliar with the original term.) Thus, associated with the Norn-like trio of legend, the word was eventually understood to mean “witchy” or “eerie,” whence the modern meaning.
The weird sisters of Shakespeare predate these ones by some centuries: