| Abu'l-Ḥasan Aḥmad ibn Jaʿfar al-Barmaki al-Nadim | |
| Other Names: | Jahza al-Barmaki |
| Father: | Jaʿfar ibn Musa |
| Birth Date: | c. 839 |
| Birth Place: | Abbasid Caliphate |
| Death Date: | June/July 936 |
| Death Place: | Wasit, Abbasid Caliphate (now Iraq) |
| Era: | Islamic Golden Age (Abbasid era) |
| Occupation: | Lute player and Author |
| Known For: | Singer, poet, and Abbasīd courtier, close Companion of Al-Muqtadir |
| Notable Works: |
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Abu'l-Ḥasan Aḥmad ibn Jaʿfar al-Barmakī al-Nadīm (839 – June/July 936), surnamed Jaḥẓa (Arabic: جحظة||popping out, bulging) and al-Ṭunbūrī, was a descendant of the Barmakid family, and a well-known scholar, singer, poet, and courtier of his time.
He was reportedly born in 839, the grandson of Musa ibn Yahya and great-grandson of the famous Yahya al-Barmaki, the vizier of Harun al-Rashid. The historian Charles Pellat describes him as "a man of very varied culture, but little religion, of doubtful morals and repulsive appearance"; he was nicknamed by the Abbasid prince and poet Ibn al-Mu'tazz, on account of his bulging eyeballs. He nevertheless was a prominent member of the courtly society of his time, and appears in multiple anecdotes, associating with the grandees of the Abbasid Caliphate's court. Little of his work survives, apart from a few poems; most of them are known through a list in the 10th-century compendium al-Fihrist, and include treatises on astrology, lute-playing, cooking, and a biography of Caliph al-Mu'tamid. He died at Wasit in June/July 936.