“Halloween“ is a direct derivation of All Saints’ Day. All Hallows in Old English means “the feast of the saints.” “Halloween,” first attested in the 16th century, is a Scottish variant of All-Hallows-Even. The “Even” meant evening.
The spelling of the word was once “Hallowe’en,” in which the “v” was elided.
The British can claim ownership of the original use of the phrase “jack-o’-lantern.” In the 17th century, it referred to a night watchman, a man who literally carried a lantern.
But it was also a nickname for strange, flickering lights seen at night over wetlands, or peat bogs, and mistaken to be fairies or ghosts. This natural phenomenon is also called ignis fatuus, which means “fool’s fire,” and will o’ the wisp.
Eventually what was called a “turnip lantern” became known as a jack-o’-lantern. Young boys used these hollowed-out and lit-up gourds to spook people.
During the medieval practice of souling, poor people would make the rounds begging for food. In return, they offered prayers for the dead on All Souls Day. [...]
Modern trick or treating is a custom borrowed from guising, which children still do in some parts of Scotland. Guising involves dressing in costume and singing a rhyme, doing a card trick, or telling a story in exchange for a sweet. The Scottish and Irish brought the custom to America in the 19th century.
The earliest reference of the term “trick or treat” in print was in 1927, in Alberta, Canada. It appears as if the practice didn’t really take hold in the U.S. until the mid-1930s...