IPA: /ˈtɒp.nɒtʃ/
KK: /tɑpˈnɑtʃ/
Of the highest quality or standard; excellent.
The restaurant is known for its topnotch service and delicious food.
Topnotch → It is formed from "top" (from Old English "top", meaning the highest point) and "notch" (from Old French "noche", meaning a cut or indentation). The word "topnotch" refers to something that is at the highest level or of the best quality.
Think of the 'highest point' ('top') and a 'cut' or 'indentation' ('notch') to remember that 'topnotch' means something of the highest quality.