Undulipodium (pl. undulipodia) A whiplike organelle that protrudes from a eukaryotic cell and is used chiefly for locomotion (e.g. motile gametes) or feeding (e.g. ciliate protoctists).

波动足（生毛体）：真核细胞表面突起的鞭状结构，主要作用为运动(如：游动精子)和摄食(如：纤毛protoctists)。