What is "nipplewort"

Nipplewort \Nip"ple*wort`\ (n[i^]p"p'l*w[^u]rt`), n. (Bot.) A yellow-flowered composite herb ( Lampsana communis), formerly used as an external application to the nipples of women; -- called also dock-cress.

n. A flowering plant, (taxlink Lapsana communis species noshow=1), that yields a milky juice.