In Roman law. A maxim, or rule, casting the responsibility for defects or deficiencies upon the seller of goods, and expressing the exact opposite of the common law rule of caveat emptor . See Wright v. Hart, 18 Wend. (N. Y.) 449. In English and American jurisprudence . Caveat venditor is sometimes used as expressing, in a rough way, the rule which governs all those cases of sales to which caveat emptor does not apply