baby's breath vs flower

baby's breath and flower both are nouns.

Word	Noun	Adjective	Verb	Adverb
baby's breath	Yes	No	No	No
flower	Yes	No	Yes	No

As nouns, flower is a hypernym of baby's breath; that is, flower is a word with a broader meaning than baby's breath:

baby's breath: tall plant with small lance-shaped leaves and numerous tiny white or pink flowers
flower: a plant cultivated for its blooms or blossoms

baby's breath (noun)	flower (noun)
tall plant with small lance-shaped leaves and numerous tiny white or pink flowers	a plant cultivated for its blooms or blossoms
	reproductive organ of angiosperm plants especially one having showy or colorful parts
	the period of greatest prosperity or productivity

baby's breath (verb)	flower (verb)
	produce or yield flowers