The Collaborative International Dictionary of English v.0.48:

Douse \Douse\ (dous), v. t. [imp. & p. p. Doused (doust); p.
   pr. & vb. n. Dousing.] [Cf. Dowse, and OD. donsen to
   strike with the fist on the back, Sw. dunsa to fall down
   violently and noisily; perh. akin to E. din.]
   1. To plunge suddenly into water; to duck; to immerse; to
      dowse. --Bp. Stillingfleet.
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   2. (Naut.) To strike or lower in haste; to slacken suddenly;
      as, douse the topsail.
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