Abstract: In linguistics, dimension words play a vital role in describing the spatial attributes of objects, such as height, length, thickness, and depth. These words are crucial for providing detailed information about the shape and size of objects, which are fundamental to our understanding of the physical world. Among these dimension words, “thin” in English and “薄” in Chinese represent an essential category of adjectives used to describe the property of thinness. This paper explores the semantics of these monosyllabic dimension words, focusing on their literal meanings, metaphorical extensions, and the cognitive and cultural factors that shape their usage in English and Chinese.