adj.私下出售的,违法的;
例句:
The mouse remained under the counter to avoid the cat.
老鼠一直呆在柜台下面以躲开那只猫.
I sense they are running under-the-counter deals on the side.
我感觉他们在另外经营非法生意(作为副业).
She reached under the counter for her purse and took out a $ 20 bill.
她从柜台下面拿出了钱包取了20块钱出来.