chichi vs last word

chichi and last word both are nouns.

Word	Noun	Adjective	Verb	Adverb
chichi	Yes	Yes	No	No
last word	Yes	No	No	No

As nouns, chichi and last word are synonyms defined as:

Other synonyms of chichi include chic, chicness, modishness, smartness, stylishness, swank.

chichi (noun)	last word (noun)
elegance by virtue of being fashionable	elegance by virtue of being fashionable
someone who dresses in a trendy fashionable way	the final statement in a verbal argument
	an authoritative statement

chichi (adjective)	last word (adjective)
affectedly trendy and fashionable