The word 咳嗽 (ké sou, "to cough") is formed through the combination of two individual characters, each constructed to evoke the physical act of coughing. The first character, 咳, prominently features the "mouth" radical (口) on the left, directly indicating the involvement of the mouth, while its right side historically contributed to its sound. The second character, 嗽, also incorporates the "mouth" radical (口) on the left, and its complex right side traditionally implied a sense of contraction or urgency, together picturing the forceful expulsion of air. Thus, the compound visually and conceptually mirrors the repetitive, throat-and-mouth-based action it describes.