(1):
(a.) Northern; belonging to, or inhabiting, a region in very far north; most northern; hence, very cold; fright, as, a hyperborean coast or atmosphere.
(2):
(a.) Of or pertaining to the region beyond the North wind, or to its inhabitants.
(3):
(n.) One of the people who lived beyond the North wind, in a land of perpetual sunshine.
(4):
(n.) An inhabitant of the most northern regions.