*borea*

a. 1. Of or pertaining to a tree, or to trees; of nature of trees. Cowley. [ 1913 Webster ]

2. Attached to, found in or upon, or frequenting, woods or trees; as, arboreal animals. [ 1913 Webster ]

Woodpeckers are eminently arboreal. Darwin. [ 1913 Webster ]

a. [ L. borealis: cf. F. boréal. See Boreas. ] 1. Northern; pertaining to the north, or to the north wind; as, a boreal bird; a boreal blast. [ 1913 Webster ]

So from their own clear north in radiant streams,
Bright over Europe bursts the boreal morn. Thomson. [ 1913 Webster ]

2. (Biogeography) Designating or pertaining to a terrestrial division consisting of the northern and mountainous parts of both the Old and the New World; -- equivalent to the Holarctic region exclusive of the Transition, Sonoran, and corresponding areas. The term is used by American authors and applied by them chiefly to the Nearctic subregion. The Boreal region includes approximately all of North and Central America in which the mean temperature of the hottest season does not exceed 18° C. (= 64.4° F.). Its subdivisions are the Arctic zone and
Boreal zone, the latter including the area between the Arctic and Transition zones. [ Webster 1913 Suppl. ]

a. [ L. hyperboreus, Gr. &unr_;; "ype`r over, beyond + &unr_;. See Boreas.] 1. (Greek Myth.) Of or pertaining to the region beyond the North wind, or to its inhabitants. [1913 Webster]

2. Northern; belonging to, or inhabiting, a region in very far north; most northern; hence, very cold; fright, as, a hyperborean coast or atmosphere. [1913 Webster]

The hyperborean or frozen sea. C. Butler (1633). [1913 Webster]

n. 1. (Greek Myth.) One of the people who lived beyond the North wind, in a land of perpetual sunshine. [ 1913 Webster ]

2. An inhabitant of the most northern regions. [ 1913 Webster ]

‖pos>n. [ NL. Linnaeus Linnæan + L. borealis northern. ] (Bot.) The twin flower which grows in cold northern climates. [ 1913 Webster ]

adj. not arboreal; not living in trees; -- of animals. Opposite of arboreal. [ WordNet 1.5 ]