Tormentil, n. [F. tormentille; cf. Pr., It., & NL. tormentilla, Sp. tormentila; all fr. L. tormentum pain. So called because it is said to allay pain. See Torment.].
A rosaceous herb (Potentilla Tormentilla), the root of which is used as a powerful astringent, and for alleviating gripes, or tormina, in diarrhea. [1913 Webster]