sick berth vs sickbay

sick berth and sickbay both are nouns.

Word	Noun	Adjective	Verb	Adverb
sick berth	Yes	No	No	No
sickbay	Yes	No	No	No

As nouns, sick berth and sickbay are synonyms defined as:

sick berth and sickbay: (nautical) a room for the treatment of the sick or injured (as on a ship)

sick berth (noun)	sickbay (noun)
(nautical) a room for the treatment of the sick or injured (as on a ship)	(nautical) a room for the treatment of the sick or injured (as on a ship)