The Collaborative International Dictionary of English v.0.48:

Floccus \Floc"cus\, n.; pl. Flocci. [L., a flock of wool.]
   1. (Zool.)
      (a) The tuft of hair terminating the tail of mammals.
      (b) A tuft of feathers on the head of young birds.
          [1913 Webster]

   2. (Bot.) A woolly filament sometimes occuring with the
      sporules of certain fungi.
      [1913 Webster]