All Hallows’ Eve—also called “Hallowe’en”—is celebrated each year on the night before “All Hallows’ Day” (or “All Saints’ Day”). The noun “hallow” refers to a “holy or consecrated person,” and “Hallowe’en” is a contraction or “Hallows” and “Eve.”
The origin of the holiday is thought to be a Christianized version of an older, Pagan Celtic Festival of the Dead, held each year at harvest time. As with so many Pagan traditions, the Church found that it was easier to re-purpose an old holiday rather than condemn and ban one.
Today, Hallowe’en has lost much of its earlier, religious meaning. Yet, still, children (and some adults) look-forward to an evening of dressing-up, revelry, and indulgence.