Definitions:
of the north or northern regions.

relating to or characteristic of the climatic zone south of the arctic, especially the cold temperate region dominated by taiga and forests of birch, poplar, and conifers

relating to or denoting the second climatic stage of the postglacial period in northern europe, between the preboreal and atlantic stages (about 9,000 to 7,500 years ago), marked by a warm, dry climate.