smashing vs dandy

smashing and dandy both are nouns.

Word	Noun	Adjective	Verb	Adverb
smashing	Yes	Yes	No	No
dandy	Yes	Yes	No	No

As adjectives, smashing and dandy are synonyms defined as:

Other synonyms of smashing include bang-up, bully, corking, cracking, great, groovy, keen, neat, nifty, not bad, old, peachy, slap-up, swell.

smashing (noun)	dandy (noun)
the act of breaking something into small pieces	a sailing vessel with two masts; a small mizzen is aft of the rudderpost
	a man who is much concerned with his dress and appearance

smashing (adjective)	dandy (adjective)
excellent	excellent