The Collaborative International Dictionary of English v.0.48:
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. [1913 Webster]The Collaborative International Dictionary of English v.0.48:
Dock-cress \Dock"-cress`\, n. (Bot.) Nipplewort. [1913 Webster]