foregone conclusion vs uncertain

foregone conclusion is a noun but uncertain is not a noun.

Word	Noun	Adjective	Verb	Adverb
foregone conclusion	Yes	No	No	No
uncertain	No	Yes	No	No

foregone conclusion (noun)	uncertain (noun)
something that is certain
an inevitable ending

foregone conclusion (adjective)	uncertain (adjective)
	not established beyond doubt; still undecided or unknown
	lacking or indicating lack of confidence or assurance
	not certain to occur; not inevitable
	not established or confirmed
	ambiguous (especially in the negative)
	not consistent or dependable
	subject to change