streambed vs creek bed

streambed and creek bed both are nouns.

Word	Noun	Adjective	Verb	Adverb
streambed	Yes	No	No	No
creek bed	Yes	No	No	No

As nouns, streambed and creek bed are synonyms defined as:

streambed and creek bed: a channel occupied (or formerly occupied) by a stream

streambed (noun)	creek bed (noun)
a channel occupied (or formerly occupied) by a stream	a channel occupied (or formerly occupied) by a stream