linear vs math

linear is not a noun while math is a noun.

Word	Noun	Adjective	Verb	Adverb
linear	No	Yes	No	No
math	Yes	No	No	No

linear (noun)	math (noun)
	a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement

linear (adjective)	math (adjective)
of or in or along or relating to a line; involving or having a single dimension
designating or involving an equation whose terms are of the first degree
of a circuit or device having an output that is proportional to the input
measured lengthwise
(of a leaf shape) long and narrow