narcotic

1. N-COUNT Narcotics are drugs such as opium or heroin which make you sleepy and stop you from feeling pain. You can also use narcotics to mean any kind of illegal drugs. 麻醉剂; 毒品

He was indicted for dealing in narcotics. 他因贩卖毒品而受到起诉。

2. ADJ If something, especially a drug, has a narcotic effect, it makes the person who uses it feel sleepy. 麻醉的

...hormones that have a narcotic effect on the immune system. …对免疫系统有麻醉作用的激素。