deluge vs Noah's flood

deluge and Noah's flood both are nouns.

Word	Noun	Adjective	Verb	Adverb
deluge	Yes	No	Yes	No
Noah's flood	Yes	No	No	No

As nouns, Noah's flood is a hyponym of deluge; that is, Noah's flood is a word with a more specific, narrower meaning than deluge:

deluge: the rising of a body of water and its overflowing onto normally dry land
Noah's flood: (Biblical) the great deluge that is said in the Book of Genesis to have occurred in the time of Noah; it was brought by God upon the earth because of the wickedness of human beings

Other hyponyms of deluge include debacle, flash flood, flashflood, Noachian deluge, Noah and the Flood, the Flood.

deluge (noun)	Noah's flood (noun)
a heavy rain	(Biblical) the great deluge that is said in the Book of Genesis to have occurred in the time of Noah; it was brought by God upon the earth because of the wickedness of human beings
the rising of a body of water and its overflowing onto normally dry land
an overwhelming number or amount

deluge (verb)	Noah's flood (verb)
fill or cover completely, usually with water
charge someone with too many tasks
fill quickly beyond capacity; as with a liquid