Wikipedia
Winterfylleth was the Anglo-Saxon or Old English name for the month of October. It marked and celebrated the beginning of winter.
The name of the month was recorded by the Venerable Bede thus:
Antiqui Anglorum populi […] annum totum in duo tempora, hiemis et aestatis dispertiebant, sex menses […] aestati tribuendo, sex reliquos hiemi; unde et mensem, quo hiemalia tempora incipiebant, Wintirfylliþ appellabant, composite nomine ab hieme et plenilunio, quia videlicet a plenilunio ejusdem mensis hiems sortiretur initium […] Wintirfylliþ potest dici compositio novo nomine hiemi pleniuni.
The old English people split the year into two seasons, summer and winter, placing six months — during which the days are longer than the nights — in summer, and the other six in winter. They called the month when the winter season began Wintirfylliþ, a word composed of "winter" and "full moon", because winter began on the first full moon of that month.
Though in modern times in this month, Halloween is celebrated in America, England and elsewhere, it is not linked to Old English tradition, though many of the customs are English in origin.
There is an English black-metal band named Winterfylleth.
Winterfylleth is an English black metal band from Manchester. Since their inception in 2007, the band has released four studio albums and have become a popular act in both the English underground metal scene and the wider international metal arena. Winterfylleth is self-described as "English heritage black metal" and is often considered to be musical 'brothers-in-arms' with fellow English black metal band Wodensthrone owing to the common lyrical and aesthetic themes they share. The band takes its name from the Old English name for the month of October.