bed of flowers vs flowerbed

bed of flowers and flowerbed both are nouns.

Word	Noun	Adjective	Verb	Adverb
bed of flowers	Yes	No	No	No
flowerbed	Yes	No	No	No

As nouns, bed of flowers and flowerbed are synonyms defined as:

Other synonyms of bed of flowers include flower bed.

bed of flowers (noun)	flowerbed (noun)
a bed in which flowers are growing	a bed in which flowers are growing