Hyphens are most commonly used to connect compound modifiers that are being used together to describe a noun. ... For example, in the sentence, “The Little Chef restaurant is top notch,” top and notch require no hyphenation because they fall after the noun they modify. Hyphens can also be used to clarify meaning.

Is top notch one word or two?

or top-notch

first-rate: a topnotch job.

Is it top notch or top notched?

If you describe someone or something as top-notch, you mean that they are of a very high standard or quality.