The study deals with one of the important topics in semantics, which is minor derivation, represented here by the justification of naming.Among the most prominent ancient linguists who studied it was Ibn Sidah (d. 458 AH) in his dictionary Al-Muhkam and Al-Muhit Al-A'zam.I noticed that he returns some justifications for naming in his dictionary, so I wanted to do a study that sheds light on those justifications.This involves searching for the reason for naming things, meaning returning them to the origin from which they came.Linguists, both ancient and modern, have been concerned with studying the justification of naming.Th- Consideration of the core root of the word whose name is being explained.