There is a difference between the geographical and the cultural use of the word.
As historian Hilda Roderick Ellis Davidson notes, paganism survived late in Scandinavia. After nearly all of Europe had given up the practices of human sacrifice, cannibalism, and the sale of women as property, the Norse were still engaging in such activities. Paganism was still widespread until the twelfth century.
Perhaps because heathen practices continued later in this region, they are more documented than in other areas. Saxony, e.g., discontinued pagan practices several centuries earlier, and few written records remain about their human sacrifices. Ellis Davidson writes:
In south Sweden can be seen hundreds of rock carvings from a still earlier time, recording rites and symbols; while at holy places like Thorsbjerg in north Germany or Skedemose on the island of Oland in the Baltic, offerings of men and animals, weapons, ornaments, ploughs and food were made over a period of centuries in the lakes and marshes, as careful excavation has now revealed.
Among the pantheon of Norse mythology, Odin was a chief or king among the deities, one of the greatest, if not the greatest, of the Norse idols. Germanic royalty sometimes claimed descent from him, and he appears in some of their genealogies.
Odin was therefore especially worshipped by aristocrats and military men. In the case of Odin, human sacrifice took the particular form of prisoners of war, as Ellis Davidson reports:
Odin was the ancestor of Scandinavian kings, and was worshipped by those who lived by their weapons and went out to plunder and conquer in many lands in the Viking Age; war captives and animals might be sacrificed to him and their bodies hung from trees.
Human sacrifice was a standard and essential feature of Nordic spirituality. As a general feature of pre-religious culture, mythology, including Norse mythology, included magic.
Magic is the attempt to manipulate natural events or human events. Sacrifice, of animals or humans, is done in an attempt to persuade some supernatural being to intervene on one’s behalf.
Moving from pre-religious societies to religious societies, attempts at magic recede, and there is more of an emphasis on forming a relationship with the deity rather than merely attempting to cajole the deity to act in one’s favor. By the 1200s, both human and animal sacrifice had become quite rare in Scandinavia.
