PENNYROYAL

noun Etymology: probably alteration of Anglo-French puliol real, from puliol ~ (ultimately from Latin puleium) + real royal Date: 1530 a European perennial mint ( Mentha pulegium ) with small aromatic leaves, an aromatic North 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