nifty vs groovy

nifty and groovy both are adjectives.

Word	Noun	Adjective	Verb	Adverb
nifty	No	Yes	No	No
groovy	No	Yes	No	No

As adjectives, nifty and groovy are synonyms defined as:

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

nifty (adjective)	groovy (adjective)
excellent	(British informal) very chic
	excellent