羊毛 (yáng máo) literally means 'sheep hair' and refers specifically to the soft, insulating fiber obtained from sheep. The first character 羊 (yáng) means 'sheep', and the second character 毛 (máo) means 'hair' or 'fur' — together they form a compound noun denoting the natural material used widely in textiles. Unlike generic terms for animal fibers, 羊毛 is precise: it only refers to wool from sheep, not from goats (which is 山羊毛, shānyáng máo) or alpacas.

This word appears frequently in contexts related to clothing, manufacturing, and agriculture — for example, when describing sweater material, wool production, or textile quality labels. In everyday speech, it’s commonly used in phrases like 羊毛衫 (yáng máo shān, 'wool sweater') or 羊毛毯 (yáng máo tǎn, 'wool blanket'). It carries no strong connotations of formality or informality and is standard across spoken and written Chinese.