| Word | Definitions | Synonyms |
|---|---|---|
| diacetylmorphine | (noun) a narcotic that is considered a hard drug; a highly addictive morphine derivative; intravenous injection provides the fastest and most intense rush | Synonyms: heroin |
| diachrony | (noun) the study of linguistic change | Synonyms: diachronic linguistics, historical linguistics |
| diacritic | (noun) a mark added to a letter to indicate a special pronunciation | Synonyms: diacritical mark |