What does Make Density Based Clusterer in Weka do?
Based on this paper, MakeDensityBasedClusterer is  a  metaclusterer  that  wraps  a  clustering  algorithm  to make  it  return  a  probability  distribution  and  density.   To  each  cluster  and  attribute,  it  fits  a discrete distribution or a symmetric normal distribution (whose minimum standard deviation is a parameter).