bud vs flower

bud and flower both are nouns.

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

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

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

Other hypernyms of bud include bloom, blossom.

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

bud (verb)	flower (verb)
develop buds	produce or yield flowers
start to grow or develop