1st vs basic

1st is not a noun while basic is a noun.

Word	Noun	Adjective	Verb	Adverb
1st	No	Yes	No	No
basic	Yes	Yes	No	No

1st (noun)	basic (noun)
	(usually in the plural) a necessary commodity for which demand is constant

1st (adjective)	basic (adjective)
preceding all others in time or space or degree	pertaining to or constituting a base or basis
	of or denoting or of the nature of or containing a base
	reduced to the simplest and most significant form possible without loss of generality
	serving as a base or starting point