economy vs economical

economy is a noun but economical is not a noun.

Word	Noun	Adjective	Verb	Adverb
economy	Yes	No	No	No
economical	No	Yes	No	No

economy (noun)	economical (noun)
an act of economizing; reduction in cost
frugality in the expenditure of money or resources
the efficient use of resources
the system of production and distribution and consumption

economy (adjective)	economical (adjective)
	of or relating to an economy, the system of production and management of material wealth
	using the minimum of time or resources necessary for effectiveness
	avoiding waste