The term narcotic (/nɑːrˈkɒtᵻk/, from ancient Greek ναρκῶ narkō, "to make numb") originally referred medically to any psychoactive compound with sleep-inducing properties. In the United States, it has since become associated with opiates and opioids, commonly morphine and heroin, as well as derivatives of many of the compounds found within raw opium latex. The primary three are morphine, codeine, and thebaine (while thebaine itself is only very mildly psychoactive, it is a crucial precursor in the vast majority of semi-synthetic opioids, such as hydrocodone). Legally speaking, the term "narcotic" is imprecisely defined and typically has negative connotations. When used in a legal context in the U.S., a narcotic drug is simply one that is totally prohibited, or one that is used in violation of governmental regulation, such as heroin or cannabis.