Pinkroot \Pink"root`\, n. 1. (Med.) The root of {Spigelia Marilandica}, used as a powerful vermifuge; also, that of {S. Anthelmia}. See definition 2 (below). 2. (Bot.) (a) A perennial North American herb ({Spigelia Marilandica}), sometimes cultivated for its showy red blossoms. Called also {Carolina pink}, {Maryland pinkroot}, and {worm grass}. (b) An annual South American and West Indian plant ({Spigelia Anthelmia}).