A-one vs tiptop

A-one is not a noun while tiptop is a noun.

Word	Noun	Adjective	Verb	Adverb
A-one	No	Yes	No	No
tiptop	Yes	Yes	No	No

As adjectives, A-one and tiptop are synonyms defined as:

Other synonyms of A-one include ace, crack, first-rate, super, top-notch, topnotch, tops.

A-one (noun)	tiptop (noun)
	the extreme top or summit
	the highest level or degree attainable; the highest stage of development

A-one (adjective)	tiptop (adjective)
of the highest quality	of the highest quality