tuft vs witches' broom

tuft and witches' broom both are nouns.

Word	Noun	Adjective	Verb	Adverb
tuft	Yes	No	No	No
witches' broom	Yes	No	No	No

As nouns, witches' broom is a hyponym of tuft; that is, witches' broom is a word with a more specific, narrower meaning than tuft:

tuft: a bunch of hair or feathers or growing grass
witches' 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 tuft include wisp, hexenbesen, staghead, witch broom, coma.

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