Rhatany \Rhat"a*ny\, Rhatanhy \Rhat"an*hy\, n. [Sp. ratania, rata[~n]a, Peruv. rata[~n]a.] The powerfully astringent root of a half-shrubby Peruvian plant ({Krameria triandra}). It is used in medicine and to color port wine. [Written also {ratany}.] {Savanilla rhatany}, the root of {Krameria Ixina}, a native of New Granada.