dandy vs old

dandy and old both are nouns.

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

As adjectives, dandy and old are synonyms defined as:

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

dandy (noun)	old (noun)
a sailing vessel with two masts; a small mizzen is aft of the rudderpost	past times
a man who is much concerned with his dress and appearance

dandy (adjective)	old (adjective)
excellent	of long duration; not new
	(used especially of persons) having lived for a relatively long time or attained a specific age
	skilled through long experience
	(used for emphasis) very familiar
	excellent
	just preceding something else in time or order
	belonging to some prior time