[pen.ny.roy.al] n [prob. by folk etymology fr. MF poullieul, modif. of L pulegium fleabane, pennyroyal] (1530) 1: a European perennial mint (Mentha pulegium) with small aromatic leaves
2: an aromatic No. American mint (Hedeoma pulegioides) that has blue or violet flowers borne in axillary tufts and yields an oil used in folk medicine or to drive away mosquitoes