tidy sum vs raft

tidy sum and raft both are nouns.

Word	Noun	Adjective	Verb	Adverb
tidy sum	Yes	No	No	No
raft	Yes	No	Yes	No

As nouns, tidy sum and raft are synonyms defined as:

tidy sum and raft: (often followed by `of') a large number or amount or extent

tidy sum (noun)	raft (noun)
(often followed by `of') a large number or amount or extent	a flat float (usually made of logs or planks) that can be used for transport or as a platform for swimmers
	a foundation (usually on soft ground) consisting of an extended layer of reinforced concrete
	(often followed by `of') a large number or amount or extent