The term 'Purgative Plant' refers to a plant known as Scammony, which is an 8-letter word. Scammony is a species of flowering plant in the family Convolvulaceae, native to the Mediterranean region. It has been used for centuries as a purgative, or laxative, due to its high concentration of anthraquinone glycosides. The plant is also known for its anti-inflammatory and antispasmodic properties.