derris
der.ris \'der-*s\ n [NL, genus name, fr. Gk, skin, fr. derein to skin - more at TEAR] 1: any of a large genus (Derris) of leguminous tropical Old World shr ubs and woody vines including sources of native fish and arrow poisons and commercial sources of rotenone 2: a preparation of derris roots and stems used as an insecticide