tiptop vs top-notch

tiptop is a noun but top-notch is not a noun.

Word	Noun	Adjective	Verb	Adverb
tiptop	Yes	Yes	No	No
top-notch	No	Yes	No	No

As adjectives, tiptop and top-notch are synonyms defined as:

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

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

tiptop (adjective)	top-notch (adjective)
of the highest quality	of the highest quality