Under the counter Definition 1 of 2Pro Tip 1/3Illegal Transactions Refers to buying or selling things in violation of the law or rules. He was caught selling watches under the counter. Pro Tip 2/3Hidden Deals Used to describe deals done secretly to avoid taxes or regulations. They offered to sell it under the counter to avoid sales tax. Pro Tip 3/3Bypassing Restrictions Implies getting something that's usually restricted or not openly sold. Prescription drugs are sometimes sold under the counter.