great deal vs deluge

great deal and deluge both are nouns.

Word	Noun	Adjective	Verb	Adverb
great deal	Yes	No	No	No
deluge	Yes	No	Yes	No

As nouns, deluge is a hyponym of great deal; that is, deluge is a word with a more specific, narrower meaning than great deal:

Other hyponyms of great deal include flood, inundation, torrent, haymow.

great deal (noun)	deluge (noun)
(often followed by `of') a large number or amount or extent	a heavy rain
	the rising of a body of water and its overflowing onto normally dry land
	an overwhelming number or amount

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