Hy′per‐bo″re‐an (?), a. [L. hyperboreus, Gr. �; υπἕρ over, beyond + �. See Boreas.] 1. (Greek Myth.) Of or pertaining to the region beyond the North wind, or to its inhabitants.
2. Northern; belonging to, or inhabiting, a region in very far north; most northern; hence, very cold; fright, as, a hyperborean coast or atmosphere.
The hyperborean or frozen sea. C. Butler (1633).