dry wash vs creek bed

dry wash and creek bed both are nouns.

Word	Noun	Adjective	Verb	Adverb
dry wash	Yes	No	No	No
creek bed	Yes	No	No	No

As nouns, creek bed is a hypernym of dry wash; that is, creek bed is a word with a broader meaning than dry wash:

dry wash: the dry bed of an intermittent stream (as at the bottom of a canyon)
creek bed: a channel occupied (or formerly occupied) by a stream

Other hypernyms of dry wash include streambed.

dry wash (noun)	creek bed (noun)
the dry bed of an intermittent stream (as at the bottom of a canyon)	a channel occupied (or formerly occupied) by a stream