Source : Webster's Revised Unabridged Dictionary (1913)

Northeastern \North`east"ern\, a.
   Of or pertaining to the northeast; northeasterly.

Source : WordNet®

northeastern
     adj 1: situated in or oriented toward the northeast; "the
            northeasterly part of the island" [syn: {northeasterly},
             {northeast}]
     2: of a region of the United States generally including the New
        England states; New York; and sometimes New Jersey and
        Pennsylvania