兔毛 (tù máo) literally means 'rabbit fur' — 兔 (tù) means 'rabbit', and 毛 (máo) means 'fur' or 'hair'. Together, they refer specifically to the soft, fine undercoat harvested from rabbits, commonly used in high-quality brushes, luxury textiles, and traditional crafts. Unlike general terms for animal hair like 动物毛 (dòngwù máo), 兔毛 emphasizes both species specificity and functional value.

This term appears frequently in contexts related to materials science, textile manufacturing, art supplies, and traditional Chinese medicine (where it’s occasionally referenced in historical formulas). It is a compound noun with no grammatical inflection — it functions as a standalone, uncountable noun in most cases, though it may be quantified with measure words like 些 (xiē) or 根 (gēn) when referring to individual hairs. The word carries neutral register and is standard in both spoken and written Mandarin.