bridal gown vs wedding gown

bridal gown and wedding gown both are nouns.

Word	Noun	Adjective	Verb	Adverb
bridal gown	Yes	No	No	No
wedding gown	Yes	No	No	No

As nouns, bridal gown and wedding gown are synonyms defined as:

Other synonyms of bridal gown include wedding dress.

bridal gown (noun)	wedding gown (noun)
a gown worn by the bride at a wedding	a gown worn by the bride at a wedding