pixie vs shrub

pixie and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
pixie	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of pixie; that is, shrub is a word with a broader meaning than pixie:

pixie: creeping evergreen shrub having narrow overlapping leaves and early white star-shaped flowers; of the pine barrens of New Jersey and the Carolinas
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of pixie include bush.

pixie (noun)	shrub (noun)
(folklore) fairies that are somewhat mischievous	a low woody perennial plant usually having several major stems
creeping evergreen shrub having narrow overlapping leaves and early white star-shaped flowers; of the pine barrens of New Jersey and the Carolinas