Source : Webster's Revised Unabridged Dictionary (1913)

Drizzle \Driz"zle\, v. i. [imp. & p. p. {Drizzled}; p. pr. & vb.
   n. {Drizzling}.] [Prop. freq. of AS. dre['o]san to fall. See
   {Dreary}.]
   To rain slightly in very small drops; to fall, as water from
   the clouds, slowly and in fine particles; as, it drizzles;
   drizzling drops or rain. ``Drizzling tears.'' --Spenser.

Source : WordNet®

drizzling
     adj : (of rain) falling lightly in very small drops; "a raw
           drizzing rain"