marginal vs minimum

marginal is not a noun while minimum is a noun.

Word	Noun	Adjective	Verb	Adverb
marginal	No	Yes	No	No
minimum	Yes	Yes	No	No

marginal (noun)	minimum (noun)
	the point on a curve where the tangent changes from negative on the left to positive on the right
	the smallest possible quantity

marginal (adjective)	minimum (adjective)
of questionable or minimal quality	the least possible
just barely adequate or within a lower limit
at or constituting a border or edge
producing at a rate that barely covers production costs