epic vs big

epic is a noun but big is not a noun.

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

epic (noun)	big (noun)
a long narrative poem telling of a hero's deeds

epic (adjective)	big (adjective)
constituting or having to do with or suggestive of a literary epic	above average in size or number or quantity or magnitude or extent
very imposing or impressive; surpassing the ordinary (especially in size or scale)	conspicuous in position or importance
	given or giving freely
	generous and understanding and tolerant
	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