Profiles of the major illicit drugs

Drug (noun): any substance used as a medicine . . . a narcotic substance or preparation . . . (verb): to stupefy by a narcotic drug. Stupefy: to make stupid or dull; or deprive of sensibility; make torpid. (The word is similar to ''stupid'': lacking in understanding . . . sluggish . . . slow-witted . . . mental dullness.)

Opiate: . . . a narcotic . . . anything restful or soothing. . . inducing sleep.

- Websterm HEROIN

A brown or white powder, refined from morphine, which is in turn extracted from the dried juice of the oriental poppy.

The Latin name of the poppy gives the clue to its narcotic effect: Papaver somniferum, or sleep-bearing poppy.

The poppy is grown in hot places remote from central authority in Southwest and Southeast Asia, Mexico, Turkey, and elsewhere.

Farmers, almost always the poorest of the poor, make a series of vertical cuts in the poppy pod 10 days after the petals have fallen. A thick, latex-like substance oozes out and turns brown. This is opium, which has been part of the lives of many Asians for millenia.

In rural Thailand, mothers blow the fumes of opium pipes into babies' faces to induce them to sleep.

In 1803 a German chemist isolated morphine, the most active ingredient in opium. It was so powerful that he named it after the Greek god of dreams, Morpheus. By 1874, morphine had been boiled with other chemicals, notably acetic anhydride, a perfectly legal substance closely related to ordinary table vinegar. Result: diacetylmorphone, or heroin.

Heroin was freely available as a pain-killer and sedative in the US and Europe until 1914. The Mayer Pharmaceutical Company advertised it as ''the sedative for coughs.'' Quacks and gypsies hawked concoctions with such names as ''Mrs. Winslow's soothing syrup,'' ''Darby's carminative,'' and ''Godfrey's cordial.''

But, just as thousands of US Civil War soldiers had become addicted to the morphine used to treat battlefield wounds in the 1860s, so many people became hooked on the new heroin as well. The 1914 Harrison Act in the US placed heroin under strict control.

Since the 1920s, doctors in almost all countries have been unable to prescribe heroin. The exception is Britain, where it may be prescribed for addicts in treatment centers.

The drug produces euphoria followed by rapid depression. Addicts frequently turn to crime to obtain the $100 or more a day they need to buy supplies. The US alone has about 500,000 heroin addicts, compared to 50,000 two decades ago.

About four metric tons of heroin enter the US illegally each year, mostly from Pakistan and Afghanistan. COCAINE

A stimulant, though it is termed a ''narcotic'' by an international convention of 1961.

It is extracted from the leaves of the coca bush, a hardy plant that gives several crops a year on the slopes of the Andes Mountains. Medically it is used as an anesthetic. But abused it is ''snorted'' through the nose, or injected in the form of cocaine hydrochloride crystals known as ''snow'' or ''flake.'' The drug excites the central nervous system, heightens alertness, removes the appetite for food, causes insomnia. It can lead to extreme irritability, delusions of persecution, and possibly to schizophrenia.

South American Indians have chewed the coca leaf for centuries to alleviate the effects of altitude and poverty. Refined cocaine has acquired a glamorous image because it is so often used by Western entertainers, athletes, and professionals. Abusers in New York appealing for help on a new ''hot line'' telephone number report spending an average of $800 a week on their habit. Some users spent $150,000 in the past year.

Some 40 to 48 metric tons are smuggled into the US each year, mostly from Colombia. About 21.5 million Americans have tried it at least once, 10.8 million of them over 26 years old. There are 4.2 million regular users, half between 18 and 25. Marijuana

The hemp plant, which for centuries has been turned into rope, is one source of marijuana.

Other potent varieties are grown in the Mideast and US. Their spiky leaves contain more than 400 chemical substances, including 60 cannabinoids. One of these chemicals is pyschoactive - delta-9-hydrocannabinol, or THC for short.

Ten years ago, most marijuana in the US and Europe contained less than .5 percent of THC, but today's ''weed'' is 10 to 15 times as strong.

One new type (sinsemilla, Spanish for ''without seeds'') has as much as 7 percent THC. Liquid hash oil can go as high as 60 percent THC.

Hashish is the resinous secretion of Mideast marijuana dried and compressed into sheets, bricks, or balls. Hash oil is a further concentration into a dark, viscous liquid.

Doctors now say that marijuana, regularly used by 20 million Americans, slows the renewal of the human life-process molecule chains known as DNA and RNA. Hence, marijuana impairs various functions of the human body.

Last year 20 percent of an estimated 10,000 to 13,000 tons of marijuana used in the US was grown domestically. Sixty percent was smuggled from Colombia, and 10 percent each from Mexico and Jamaica. Much European marijuana comes from Lebanon's Bekaa Valley and from Morocco. New York street prices

Here are typical street prices for drugs traded illegally as of November 1983 . Heroin

For 10 kilograms (kg.) of opium, which makes about 1 kg. of heroin, the remote farmer gets about $500. (One kilogram equals about 2.2 lbs.) On the street in New York, 1 kg. of heroin is worth $1.4 million. Cocaine

To the Andean farmer, 250 kg. of coca leaves (equal to 2.5 kg. of coca paste or 1 kg. of cocaine) might fetch $200. On the street, 1kg. of cocaine is now $ 650,000 (before recent glut: $1 million). Marijuana

A Colombian grower may receive $8.80 per kg. On the street, the dealer can receive $1,170 per kg. Hashish can fetch $3,660 per kg; hash oil: $17,850 per kg. Dangerous man-made drugs

Average street value: $4,990 per kg.

Sources: New York customs office of US Treasury Dept. and US State Dept.m