The Collaborative International Dictionary of English v.0.48:

Floccule \Floc"cule\, n. [See Flocculus.]
   1. A detached mass of loosely fibrous structure like a
      shredded tuft of wool.
      [Webster 1913 Suppl.]

   2. (Chem.) Specif.: A small particle of an insoluble
      substance formed in a liquid by the union of smaller
      particles.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

floccule
    n 1: a small loosely aggregated mass of flocculent material
         suspended in or precipitated from a liquid [syn:
         floccule, floc]