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.
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   2. Coming from the northwest; as, a northwest wind.
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   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.
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The Collaborative International Dictionary of English v.0.48:

Passage \Pas"sage\, n. [F. passage. See Pass, v. i.]
   1. The act of passing; transit from one place to another;
      movement from point to point; a going by, over, across, or
      through; as, the passage of a man or a carriage; the
      passage of a ship or a bird; the passage of light; the
      passage of fluids through the pores or channels of the
      body.
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            What! are my doors opposed against my passage!
                                                  --Shak.
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   2. Transit by means of conveyance; journey, as by water,
      carriage, car, or the like; travel; right, liberty, or
      means, of passing; conveyance.
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            The ship in which he had taken passage. --Macaulay.
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   3. Price paid for the liberty to pass; fare; as, to pay one's
      passage.
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   4. Removal from life; decease; departure; death. [R.] "Endure
      thy mortal passage." --Milton.
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            When he is fit and season'd for his passage. --Shak.
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   5. Way; road; path; channel or course through or by which one
      passes; way of exit or entrance; way of access or transit.
      Hence, a common avenue to various apartments in a
      building; a hall; a corridor.
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            And with his pointed dart
            Explores the nearest passage to his heart. --Dryden.
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            The Persian army had advanced into the . . .
            passages of Cilicia.                  --South.
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   6. A continuous course, process, or progress; a connected or
      continuous series; as, the passage of time.
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            The conduct and passage of affairs.   --Sir J.
                                                  Davies.
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            The passage and whole carriage of this action.
                                                  --Shak.
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   7. A separate part of a course, process, or series; an
      occurrence; an incident; an act or deed. "In thy passages
      of life." --Shak.
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            The . . . almost incredible passage of their
            unbelief.                             --South.
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   8. A particular portion constituting a part of something
      continuous; esp., a portion of a book, speech, or musical
      composition; a paragraph; a clause.
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            How commentators each dark passage shun. --Young.
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   9. Reception; currency. [Obs.] --Sir K. Digby.
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   10. A pass or en encounter; as, a passage at arms.
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             No passages of love
             Betwixt us twain henceforward evermore. --Tennyson.
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   11. A movement or an evacuation of the bowels.
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   12. In parliamentary proceedings:
       (a) The course of a proposition (bill, resolution, etc.)
           through the several stages of consideration and
           action; as, during its passage through Congress the
           bill was amended in both Houses.
       (b) The advancement of a bill or other proposition from
           one stage to another by an affirmative vote; esp.,
           the final affirmative action of the body upon a
           proposition; hence, adoption; enactment; as, the
           passage of the bill to its third reading was delayed.
           "The passage of the Stamp Act." --D. Hosack.
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                 The final question was then put upon its
                 passage.                         --Cushing.
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   In passage, in passing; cursorily. "These . . . have been
      studied but in passage." --Bacon.

   Middle passage, Northeast passage, Northwest passage.
      See under Middle, Northeast, etc.

   Of passage, passing from one place, region, or climate, to
      another; migratory; -- said especially of birds. "Birds of
      passage." --Longfellow.

   Passage hawk, a hawk taken on its passage or migration.

   Passage money, money paid for conveyance of a passenger, --
      usually for carrying passengers by water.
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   Syn: Vestibule; hall; corridor. See Vestibule.
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WordNet (r) 3.0 (2006):

Northwest Passage
    n 1: a water route between the Atlantic Ocean and the Pacific
         Ocean along the northern coast of North America; Europeans
         since the 16th century had searched for a short route to
         the Far East before it was successfully traversed by Roald
         Amundsen (1903-1906)