Meaning

noun a long backless sofa (usually with pillows against a wall)

noun a Muslim council of state

noun a collection of Persian or Arabic poems (usually by one author)

originBorrowed from French, from Ottoman Turkish دیوان (divan), from Classical Persian دیوان (dēwān), from Middle Persian d(p)ywʾn' (dēwān, “archive, collected writings”), from Sumerian 𒁾 (dub). Compare mattress, from Arabic (both of Middle Eastern origin, due to the local custom of lying on padding on floor being foreign to Europeans). Doublet of dewan, douane, and diwaniya.

Etymology from Wiktionary, CC BY-SA 3.0