bud vs blossom

bud and blossom both are nouns.

Word	Noun	Adjective	Verb	Adverb
bud	Yes	No	Yes	No
blossom	Yes	No	Yes	No

As nouns, blossom is a hypernym of bud; that is, blossom is a word with a broader meaning than bud:

bud: a partially opened flower
blossom: reproductive organ of angiosperm plants especially one having showy or colorful parts

Other hypernyms of bud include bloom, flower.

bud (noun)	blossom (noun)
a swelling on a plant stem consisting of overlapping immature leaves or petals	reproductive organ of angiosperm plants especially one having showy or colorful parts
a partially opened flower	the period of greatest prosperity or productivity

bud (verb)	blossom (verb)
develop buds	develop or come to a promising stage
start to grow or develop	produce or yield flowers