tussock vs witch broom

tussock and witch broom both are nouns.

Word	Noun	Adjective	Verb	Adverb
tussock	Yes	No	No	No
witch broom	Yes	No	No	No

As nouns, witch broom is a hyponym of tussock; that is, witch broom is a word with a more specific, narrower meaning than tussock:

tussock: a bunch of hair or feathers or growing grass
witch broom: an abnormal tufted growth of small branches on a tree or shrub caused by fungi or insects or other physiological disturbance

Other hyponyms of tussock include wisp, hexenbesen, staghead, witches' broom, coma.

tussock (noun)	witch broom (noun)
a bunch of hair or feathers or growing grass	an abnormal tufted growth of small branches on a tree or shrub caused by fungi or insects or other physiological disturbance