Synonyms for Pennyroyal (same or very similar meaning)
WordNet sense 1 (Eurasian perennial mint have small lilac-blue flowers and ovate leaves; yields an aromatic oil):
Mentha pulegiumWordNet sense 2 (erect hairy branching American herb having purple-blue flowers; yields an essential oil used as an insect repellent and sometimes in folk medicine):
American pennyroyal, Hedeoma pulegioidesFrom the ODE community, based on WordNetadd/edit