topnotch vs top-notch

topnotch and top-notch both are adjectives.

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

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

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

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