The Collaborative International Dictionary of English v.0.48:

Mizzle \Miz"zle\, n.
   Mist; fine rain.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mizzle \Miz"zle\, v. i. [imp. & p. p. Mizzled; p. pr. & vb. n.
   Mizzling.] [See Misle, and cf. Mistle.]
   1. To rain in very fine drops; to drizzle. --Spenser.
      [1913 Webster]

   2. To take one's self off; to go. [Slang]
      [1913 Webster]

            As long as George the Fourth could reign, he
            reigned,
            And then he mizzled.                  --Epigram,
                                                  quoted by
                                                  Wright.
      [1913 Webster]

WordNet (r) 3.0 (2006):

mizzle
    n 1: very light rain; stronger than mist but less than a shower
         [syn: drizzle, mizzle]
    v 1: rain lightly; "When it drizzles in summer, hiking can be
         pleasant" [syn: drizzle, mizzle]