The Collaborative International Dictionary of English v.0.48:

Coast \Coast\ (k[=o]st), n. [OF. coste, F. c[^o]te, rib, hill,
   shore, coast, L. costa rib, side. Cf. Accost, v. t.,
   Cutlet.]
   1. The side of a thing. [Obs.] --Sir I. Newton.
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   2. The exterior line, limit, or border of a country; frontier
      border. [Obs.]
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            From the river, the river Euphrates, even to the
            uttermost sea, shall your coast be.   --Deut. xi.
                                                  24.
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   3. The seashore, or land near it.
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            He sees in English ships the Holland coast.
                                                  --Dryden.
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            We the Arabian coast do know
            At distance, when the species blow.   --Waller.
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   The coast is clear, the danger is over; no enemy in sight.
      --Dryden. Fig.: There are no obstacles. "Seeing that the
      coast was clear, Zelmane dismissed Musidorus." --Sir P.
      Sidney.

   Coast guard.
      (a) A body of men originally employed along the coast to
          prevent smuggling; now, under the control of the
          admiralty, drilled as a naval reserve. [Eng.]
      (b) The force employed in life-saving stations along the
          seacoast. [U. S.]

   Coast rat (Zool.), a South African mammal (Bathyergus
      suillus), about the size of a rabbit, remarkable for its
      extensive burrows; -- called also sand mole.

   Coast waiter, a customhouse officer who superintends the
      landing or shipping of goods for the coast trade. [Eng.]
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