Comfrey

n. [ Prob. from F. conferve, L. conferva, fr. confervere to boil together, in medical language, to heal, grow together. So called on account of its healing power, for which reason it was also called consolida. ] (Bot.) A rough, hairy, perennial plant of several species, of the genus Symphytum. [ 1913 Webster ]

☞ A decoction of the mucilaginous root of the “common comfrey” (Symphytum officinale) is used in cough mixtures, etc.; and the gigantic “prickly comfrey” (Symphytum asperrimum) is somewhat cultivated as a forage plant. [ 1913 Webster ]