spick-and-span vs spick

spick-and-span is not a noun while spick is a noun.

Word	Noun	Adjective	Verb	Adverb
spick-and-span	No	Yes	No	No
spick	Yes	Yes	No	No

As adjectives, spick-and-span and spick are synonyms defined as:

Other synonyms of spick-and-span include immaculate, speckless, spic-and-span, spic, spotless.

spick-and-span (noun)	spick (noun)
	(ethnic slur) offensive term for persons of Latin American descent

spick-and-span (adjective)	spick (adjective)
completely neat and clean	completely neat and clean
conspicuously new