Nişanyan Sözlük is a comprehensive Turkish language dictionary developed by Sevan Nişanyan. First published in 2002 under the title "Sözlerin Soyağacı," the dictionary's eighth revised and expanded edition was released inThis dictionary aims to document the origins and historical evolution of Turkish words in standard contemporary written language, rather than providing current definitions.

The dictionary's word selection criteria are strict, excluding proper nouns, words with limited modern usage, technical terminologies, and focusing on words commonly found in Turkish texts sinceEntries also include foreign-origin words used in Turkish without quotation marks. Nişanyan Sözlük is a result of continuous effort since 1995, with daily updates and corrections to entries.