The Collaborative International Dictionary of English v.0.48:

Northwest \North`west"\, adv.
   Toward the northwest.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Northwest \North`west"\, n. [AS. nor[eth]west.]
   1. The point in the horizon between the north and west, and
      equally distant from each; the northwest part or region.
      [1913 Webster]

   2. The northwestern part of the contiguous forty-eight states
      of the United States, especially the states of Washington
      and Oregon. [U.S.]
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Northwest \North`west"\, a.
   1. Pertaining to, or in the direction of, the point between
      the north and west; being in the northwest; toward the
      northwest, or coming from the northwest; as, the northwest
      coast.
      [1913 Webster]

   2. Coming from the northwest; as, a northwest wind.
      [1913 Webster]

   Northwest passage, a passage or communication by sea
      between the Atlantic and Pacific oceans along the north
      coast of America, long sought for by navigators.
      [1913 Webster]

WordNet (r) 3.0 (2006):

northwest
    adv 1: to, toward, or in the northwest [syn: northwest,
           north-west, nor'-west]
    adj 1: situated in or oriented toward the northwest [syn:
           northwestern, northwesterly, northwest]
    2: coming from the northwest; "northwesterly winds" [syn:
       northwesterly, northwest]
    n 1: the northwestern region of the United States [syn:
         Northwest, northwestern United States]
    2: the direction corresponding to the northwestward compass
       point
    3: the compass point midway between north and west; at 315
       degrees [syn: northwest, nor'-west, northwestward,
       NW]
    4: a location in the northwestern part of a country, region, or
       city