unfavourable vs minus

unfavourable is not a noun while minus is a noun.

Word	Noun	Adjective	Verb	Adverb
unfavourable	No	Yes	No	No
minus	Yes	Yes	No	No

unfavourable (noun)	minus (noun)
	an arithmetic operation in which the difference between two numbers is calculated

unfavourable (adjective)	minus (adjective)
(of winds or weather) tending to hinder or oppose	on the negative side or lower end of a scale
not encouraging or approving or pleasing	involving disadvantage or harm
involving or creating circumstances detrimental to success or effectiveness