silver-bush vs shrub

silver-bush and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
silver-bush	Yes	No	No	No
shrub	Yes	No	No	No

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

silver-bush: silvery hairy European shrub with evergreen foliage and pale yellow flowers
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of silver-bush include bush.

silver-bush (noun)	shrub (noun)
deciduous unarmed North American shrub with silvery leaves and fruits	a low woody perennial plant usually having several major stems
silvery hairy European shrub with evergreen foliage and pale yellow flowers