tussock vs cluster

tussock and cluster both are nouns.

Word	Noun	Adjective	Verb	Adverb
tussock	Yes	No	No	No
cluster	Yes	No	Yes	No

As nouns, cluster is a hypernym of tussock; that is, cluster is a word with a broader meaning than tussock:

Other hypernyms of tussock include bunch, clump, clustering.

tussock (noun)	cluster (noun)
a bunch of hair or feathers or growing grass	a grouping of a number of similar things

tussock (verb)	cluster (verb)
	gather or cause to gather into a cluster
	come together as in a cluster or flock