upper berth vs berth

upper berth and berth both are nouns.

Word	Noun	Adjective	Verb	Adverb
upper berth	Yes	No	No	No
berth	Yes	No	Yes	No

As nouns, berth is a hypernym of upper berth; that is, berth is a word with a broader meaning than upper berth:

Other hypernyms of upper berth include built in bed, bunk.

upper berth (noun)	berth (noun)
the higher of two berths	a job in an organization
	a bed on a ship or train; usually in tiers
	a place where a craft can be made fast

upper berth (verb)	berth (verb)
	secure in or as if in a berth or dock
	come into or dock at a wharf
	provide with a berth