Al-Mu'jam Al-Kabeer is a comprehensive Arabic dictionary compiled by Ibn Al-Atheer in the 13th century. It serves as a vital resource for understanding the Arabic language, providing definitions, synonyms, and examples of usage for a wide range of words. The dictionary is notable for its systematic organization, categorizing words based on their roots. This method allows users to easily trace the meanings and derivations of words, making it an essential tool for scholars, students, and anyone interested in Arabic linguistics.