bed of flowers vs flower bed

bed of flowers and flower bed both are nouns.

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

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

Other synonyms of bed of flowers include flowerbed.

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