Definition from Wiktionary, the free dictionary
opiate (not comparable)
- Relating to, resembling, or containing opium.
- Soporific; inducing sleep or sedation.
- Deadening; causing apathy or dullness.
- A drug, hormone or other substance derived from or related to opium.
- Something that dulls the senses and induces a false and unrealistic sense of contentment.
drug, hormone or other substance derived from or related to opium
- (transitive) To treat with an opiate drug.
See also 
- vocative masculine singular of opiātus