Applying a semantic approach is a scientific approach to meaning and a modern research method in studying the Holy Quran. Synonymy is one of the most well-known conceptual relationships that has been of interest to grammarians for a long time. However, it should be noted that there is no absolute synonymy in any language; that is, no two words can be found that can replace each other in all sentences. The authors' aim in this study was to analyze the semantic features of the words "بحر" and "یمّ" in the verses of the Holy Quran using a descriptive-analytical approach. Many interpretations have taken the word "یمّ" to mean "بحر." Regarding the difference between these two words and based on an examination of all verses and considering the context and syntagmatic and paradigmatic relationships, it was concluded that the word "یمّ" is used only in the context of punishment, retribution, and fear, whereas "بحر" is more general. It can be used both in contexts of divine retribution and mercy, with its use in the context of divine mercy being more prevalent. Additionally, "یمّ" refers to a part of the sea that is close to the shore, covering the area from the middle of the sea to the shore. In contrast, the term "بحر" refers to the entire sea. The word "بحر" appears 41 times in the Holy Quran in singular, dual, and plural forms, while "یمّ" is mentioned 8 times, particularly in the story of Prophet Moses.