malum prohibitum
/ˈmeɪləm prəʊˈhɪbɪtəm/ /ˈmaləm prəʊˈhɪbɪtəm/noun
Something which is not intrinsically wicked, but which is regarded as wrong because it contravenes a law or regulation. Also as adjective: evil by convention rather than by inherent nature.
Origin
Early 18th century; earliest use found in Robert Atkyns. From post-classical Latin malum prohibitum from classical Latin malum an evil thing (use as noun of neuter of malus bad: see mal-) + prohibitum forbidden (neuter of past participle of prohibere); compare malum in se.