bloom vs chrysanthemum

bloom and chrysanthemum both are nouns.

Word	Noun	Adjective	Verb	Adverb
bloom	Yes	No	Yes	No
chrysanthemum	Yes	No	No	No

As nouns, chrysanthemum is a hyponym of bloom; that is, chrysanthemum is a word with a more specific, narrower meaning than bloom:

bloom: reproductive organ of angiosperm plants especially one having showy or colorful parts
chrysanthemum: the flower of a chrysanthemum plant

Other hyponyms of bloom include floret, floweret, apetalous flower, inflorescence, ray floret, ray flower, bud.

bloom (noun)	chrysanthemum (noun)
a powdery deposit on a surface	any of numerous perennial Old World herbs having showy brightly colored flower heads of the genera Chrysanthemum, Argyranthemum, Dendranthema, Tanacetum; widely cultivated
reproductive organ of angiosperm plants especially one having showy or colorful parts	the flower of a chrysanthemum plant
the organic process of bearing flowers
a rosy color (especially in the cheeks) taken as a sign of good health
the best time of youth
the period of greatest prosperity or productivity

bloom (verb)	chrysanthemum (verb)
produce or yield flowers