broad vs big

broad is a noun but big is not a noun.

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

broad (noun)	big (noun)
slang term for a woman

broad (adjective)	big (adjective)
having great (or a certain) extent from one side to the other	above average in size or number or quantity or magnitude or extent
showing or characterized by broad-mindedness	conspicuous in position or importance
lacking subtlety; obvious	given or giving freely
broad in scope or content	generous and understanding and tolerant
not detailed or specific	marked by intense physical force
being at a peak or culminating point	significant
very large in expanse or scope	prodigious
(of speech) heavily and noticeably regional	serious or severe
	loud and firm
	(of animals) fully developed
	in an advanced stage of pregnancy
	feeling self-importance
	exhibiting self-importance