which is derived from Old Irish and means roughly "summer's end". This was a Gaelic festival celebrated mainly in Ireland and Scotland.This festival celebrates the end of the "lighter half" of the year and beginning of the "darker half", and is sometimes regarded as the "Celtic New Year".The celebration has some elements of a festival of the dead. The ancient Celts believed that the border between this world and the Other world became thin on Samhain, allowing spirits (both harmless and harmful) to pass through. The family's ancestors were honored and invited home whilst harmful spirits were warded off. It is believed that the need to ward off harmful spirits led to the wearing of costumes and masks. Their purpose was to disguise oneself as a harmful spirit and thus avoid harm.