big vs grand

big is not a noun while grand is a noun.

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

big (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

big (adjective)	grand (adjective)
above average in size or number or quantity or magnitude or extent	used of a person's appearance or behavior; befitting an eminent person
conspicuous in position or importance	extraordinarily good or great; used especially as intensifiers
given or giving freely	the most important and magnificent in adornment
generous and understanding and tolerant	of behavior that is impressive and ambitious in scale or scope
marked by intense physical force	large and impressive in physical size or extent
significant	of high moral or intellectual value; elevated in nature or style
prodigious	of or befitting a lord
serious or severe	ostentatiously rich and superior in quality
loud and firm
(of animals) fully developed
in an advanced stage of pregnancy
feeling self-importance
exhibiting self-importance