fourth deck vs orlop deck

fourth deck and orlop deck both are nouns.

Word	Noun	Adjective	Verb	Adverb
fourth deck	Yes	No	No	No
orlop deck	Yes	No	No	No

As nouns, fourth deck and orlop deck are synonyms defined as:

Other synonyms of fourth deck include orlop.

fourth deck (noun)	orlop deck (noun)
the fourth or lowest deck	the fourth or lowest deck