bistort

noun

bis·​tort ˈbis-ˌtȯrt 

bis-ˈtȯrt

: any of several polygonums

especially : a Eurasian perennial herb (Polygonum bistorta) with twisted roots used as astringents

Word History

Etymology

Middle French bistorte, from Medieval Latin *bistorta, from Latin bis + torta, feminine of tortus, past participle of torquēre to twist — more at torture entry 1

First Known Use

1578, in the meaning defined above