couchette vs berth

couchette and berth both are nouns.

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

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

Other hypernyms of couchette include built in bed, bunk.

couchette (noun)	berth (noun)
a compartment on a European passenger train; contains 4 to 6 berths for sleeping	a job in an organization
a sleeping berth in a couchette compartment.	a bed on a ship or train; usually in tiers
	a place where a craft can be made fast

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