important vs grand

important is not a noun while grand is a noun.

Word	Noun	Adjective	Verb	Adverb
important	No	Yes	No	No
grand	Yes	Yes	No	No

important (noun)	grand (noun)
	a piano with the strings on a horizontal harp-shaped frame; usually supported by three legs
	the cardinal number that is the product of 10 and 100

important (adjective)	grand (adjective)
of great significance or value	used of a person's appearance or behavior; befitting an eminent person
of extreme importance; vital to the resolution of a crisis	extraordinarily good or great; used especially as intensifiers
important in effect or meaning	the most important and magnificent in adornment
having or suggesting a consciousness of high position	of behavior that is impressive and ambitious in scale or scope
having authority or ascendancy or influence	large and impressive in physical size or extent
	of high moral or intellectual value; elevated in nature or style
	of or befitting a lord
	ostentatiously rich and superior in quality