favourable vs plus

favourable is not a noun while plus is a noun.

Word	Noun	Adjective	Verb	Adverb
favourable	No	Yes	No	No
plus	Yes	Yes	No	No

favourable (noun)	plus (noun)
	the arithmetic operation of summing; calculating the sum of two or more numbers
	a useful or valuable quality

favourable (adjective)	plus (adjective)
(of winds or weather) tending to promote or facilitate	on the positive side or higher end of a scale
encouraging or approving or pleasing	involving advantage or good
giving an advantage
presaging or likely to bring good luck or a good outcome