dashing vs gallant

dashing is not a noun while gallant is a noun.

Word	Noun	Adjective	Verb	Adverb
dashing	No	Yes	No	No
gallant	Yes	Yes	No	No

As adjectives, dashing and gallant are synonyms defined as:

dashing (noun)	gallant (noun)
	a man who attends or escorts a woman
	a man who is much concerned with his dress and appearance

dashing (adjective)	gallant (adjective)
marked by up-to-dateness in dress and manners	unflinching in battle or action
lively and spirited	being attentive to women like an ideal knight
	having or displaying great dignity or nobility
	lively and spirited