heroic vs big

heroic is a noun but big is not a noun.

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

heroic (noun)	big (noun)
a verse form suited to the treatment of heroic or elevated themes; dactylic hexameter or iambic pentameter

heroic (adjective)	big (adjective)
relating to or characteristic of heroes of antiquity	above average in size or number or quantity or magnitude or extent
having or displaying qualities appropriate for heroes	conspicuous in position or importance
showing extreme courage; especially of actions courageously undertaken in desperation as a last resort	given or giving freely
of behavior that is impressive and ambitious in scale or scope	generous and understanding and tolerant
very imposing or impressive; surpassing the ordinary (especially in size or scale)	marked by intense physical force
	significant
	prodigious
	serious or severe
	loud and firm
	(of animals) fully developed
	in an advanced stage of pregnancy
	feeling self-importance
	exhibiting self-importance