spacious vs broad

spacious is not a noun while broad is a noun.

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

As adjectives, spacious and broad are synonyms defined as:

Other synonyms of spacious include wide.

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

spacious (adjective)	broad (adjective)
(of buildings and rooms) having ample space	having great (or a certain) extent from one side to the other
very large in expanse or scope	showing or characterized by broad-mindedness
	lacking subtlety; obvious
	broad in scope or content
	not detailed or specific
	being at a peak or culminating point
	very large in expanse or scope
	(of speech) heavily and noticeably regional