The word 安眠药 (ānmíanyào), meaning "sleeping pill", is a straightforward compound formed by combining three meaningful characters: 安 (ān, "peaceful/calm"), 眠 (mián, "sleep"), and 药 (yào, "medicine/drug"). It follows a logical, descriptive structure where "安眠" (peaceful sleep) acts as a modifier describing the purpose or effect, and "药" (medicine) is the head noun indicating the category. Thus, the term literally translates to "peaceful-sleep medicine", efficiently defining its function through the semantic sum of its parts, which is a common method of word formation in Chinese.