WordRel.com

• a heavy dull sound (as made by impact of heavy objects)

  synonym	clunkthudthumpthumping
  hypernym	sound

• a grouping of a number of similar things

  synonym	bunchclusterclustering
  hypernym	agglomeration
  hyponym	knotswadtufttussock
  instance hyponym	Northern CrossOmega CentauriPleiades

• a compact mass

  synonym	ballchunkclodgloblump
  hypernym	agglomeration
  hyponym	clewclotcoagulumgob

• gather or cause to gather into a cluster

  synonym	bunchbundlecluster
  hypernym	form
  hyponym	agglomerate

• walk clumsily

  synonym	clomp
  hypernym	walk

• come together as in a cluster or flock

  synonym	clusterconstellateflock
  hypernym	assembleforegatherforgathergathermeet
  hyponym	bunchbunch togetherbunch uphuddlehuddle together

• make or move along with a sound as of a horse's hooves striking the ground

  synonym	clopclunkplunk
  hypernym	gosound