mimosa vs buck's fizz

mimosa and buck's fizz both are nouns.

Word	Noun	Adjective	Verb	Adverb
mimosa	Yes	No	No	No
buck's fizz	Yes	No	No	No

As nouns, mimosa and buck's fizz are synonyms defined as:

mimosa and buck's fizz: a mixed drink containing champagne and orange juice

mimosa (noun)	buck's fizz (noun)
a mixed drink containing champagne and orange juice	a mixed drink containing champagne and orange juice
any of various tropical shrubs or trees of the genus Mimosa having usually yellow flowers and compound leaves
evergreen Australasian tree having white or silvery bark and young leaves and yellow flowers