great deal vs torrent

great deal and torrent both are nouns.

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

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

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

great deal (noun)	torrent (noun)
(often followed by `of') a large number or amount or extent	a violently fast stream of water (or other liquid)
	a heavy rain
	an overwhelming number or amount