addition vs add

addition is a noun but add is not a noun.

Word	Noun	Adjective	Verb	Adverb
addition	Yes	No	No	No
add	No	No	Yes	No

addition (noun)	add (noun)
the arithmetic operation of summing; calculating the sum of two or more numbers
the act of adding one thing to another
a component that is added to something to improve it
a suburban area laid out in streets and lots for a future residential area
something added to what you already have
a quantity that is added

addition (verb)	add (verb)
	make an addition (to); join or combine or unite with others; increase the quality, quantity, size or scope of
	make an addition by combining numbers
	determine the sum of
	state or say further
	bestow a quality on
	constitute an addition