Kitab al-Addad (The Book of Opposites/Antonyms) by Muhammad ibn al-Qasim al-Anbari is a pivotal work in Arabic lexicography and linguistics. This scholarly treatise delves into the fascinating phenomenon of 'addad', words that have opposite or contradictory meanings within the same lexical entry. Al-Anbari meticulously collects, analyzes, and explains these intricate linguistic paradoxes, drawing from a vast array of classical Arabic poetry, proverbs, and Quranic verses. His profound insights shed light on the semantic richness and complexity of the Arabic language, making this book an indispensable resource for students, scholars, and anyone interested in the nuances of classical Arabic vocabulary and its historical development. It showcases al-Anbari's erudition and his significant contribution to Arabic philology.