defters

Defter is a Turkish noun meaning a notebook, ledger, or diary. The plural form in Turkish is defterler. In the Ottoman Empire, defter designated a register or census book used to record households, taxes, and land tenure. Notable examples include the tahrir defteri (survey or tax register) and other official ledgers. The term derives from the Arabic daftar, meaning a book or register.

In modern Turkish, defter can describe a blank notebook for writing or note-taking, as well as a ledger used in accounting or administration. Common compound terms include çalışma defteri (work notebook), kayıt defteri (register book), and muhasebe defteri (accounting ledger). The plural defterler refers to multiple notebooks or ledgers.

Historically, defters were handwritten on parchment or paper and bound as ledgers or diaries. Ottoman defters, especially the tax and census registers, are important primary sources for scholars studying population, taxation, and landholding in the medieval and early modern periods. Today the term remains widespread in Turkish, applied to both personal notebooks and official record books, with digital formats increasingly common in contemporary usage.