Modifiers matching opiate:

• analgesic,
• heavy,
• prescribed,
• addictive,
• external,
• individual,
• lipophilic,
• natural,
• iv,
• illegal,
• pharmaceutical,
• synthetic,
• exogenous,
• narcotic,
• medicinal,
• oral,
• medical,
• traditional,
• illicit,
• hydrophilic,
• pure,
• potent,
• semisynthetic,
• powerful,
• strong,
• common,
• conventional,

Simple categories matching illicit:

• practice,
• drink,
• substance,
• drug,
• conduct,
• commodity,
• opiate,
• article,
• activity,
• business,
• weaponry,
• stimulant,
• compound,
• behavior,
• material,
• narcotic,
• endeavor,
• amphetamine,
• neurotoxin,