The Collaborative International Dictionary of English v.0.48:

Bow \Bow\ (b[=o]), n. [Icel. b[=o]gr shoulder, bow of a ship.
   See Bough.]
   [1913 Webster]
   1. (Naut.) The bending or rounded part of a ship forward; the
      stream or prow.
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   2. (Naut.) One who rows in the forward part of a boat; the
      bow oar.
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   Bow chaser (Naut.), a gun in the bow for firing while
      chasing another vessel. --Totten.
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   Bow piece, a piece of ordnance carried at the bow of a
      ship.

   On the bow (Naut.), on that part of the horizon within
      45[deg] on either side of the line ahead. --Totten.
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The Collaborative International Dictionary of English v.0.48:

Chaser \Chas"er\, n.
   1. One who or that which chases; a pursuer; a driver; a
      hunter.
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   2. (Naut.) Same as Chase gun, esp. in terms bow chaser
      and stern chaser. See under Bow, Stern.
      [1913 Webster]