dressed to the nines vs spiffed up

dressed to the nines and spiffed up both are adjectives.

Word	Noun	Adjective	Verb	Adverb
dressed to the nines	No	Yes	No	No
spiffed up	No	Yes	No	No

As adjectives, dressed to the nines and spiffed up are synonyms defined as:

dressed to the nines and spiffed up: dressed in fancy or formal clothing

Other synonyms of dressed to the nines include dolled up, dressed-up, dressed, dressed to kill, spruced up, togged up.

dressed to the nines (adjective)	spiffed up (adjective)
dressed in fancy or formal clothing	dressed in fancy or formal clothing