swell vs nifty

swell is a noun but nifty is not a noun.

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

As adjectives, swell and nifty are synonyms defined as:

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

swell (noun)	nifty (noun)
a crescendo followed by a decrescendo
the undulating movement of the surface of the open sea
a rounded elevation (especially one on an ocean floor)
a man who is much concerned with his dress and appearance

swell (adjective)	nifty (adjective)
excellent	excellent

swell (verb)	nifty (verb)
expand abnormally
cause to become swollen
increase in size, magnitude, number, or intensity
come up, as of a liquid
become filled with pride, arrogance, or anger
come up (as of feelings and thoughts, or other ephemeral things)