Definition of pennyroyal in English:



  • Either of two small-leaved plants of the mint family, used in herbal medicine.

    A creeping Eurasian plant (Mentha pulegium), and American pennyroyal (Hedeoma pulegioides), family Labiatae

    • ‘Safflower is simply a safe cooking oil, but pennyroyal is known to have potential abortive effects.’
    • ‘Herbal flea collars containing essential oils such as pennyroyal, eucalyptus and citronella can also prevent fleas and ticks from landing on your pet.’
    • ‘Mint, lemon balm, pennyroyal, chives, chamomile, mayflower, and summer savory are a few herbs perfectly suited to this microclimate.’
    • ‘Some herbal treatments, such as citrus extracts or pennyroyal, can be toxic to pets and humans.’
    • ‘Some herbs that repel fleas include: juniper, pennyroyal, citronella, eucalyptus, cedar and Canadian fleabane.’
    • ‘Then there's pennyroyal, a name for the mint Menthe pulegium, once prized as a medicinal herb.’
    • ‘Essential oils from allspice, basil, cedar, cinnamon, citronella, garlic, geranium, lavender, pennyroyal, peppermint, pine, rosemary, and thyme have been reported to have repellent properties.’
    • ‘These include pennyroyal (fatal if ingested), tea tree, rosemary and eucalyptus oils.’
    • ‘For some reason it always showed up in the potted garden and it particularly liked rooming with the pennyroyal.’
    • ‘This also is true of many herbal tablets, capsules and extracts, including black or blue cohosh, ephedra, dong quai, feverfew, juniper, pennyroyal, St. John's wort, rosemary and thuja.’


Mid 16th century: from Anglo-Norman French puliol (based on Latin pulegium ‘thyme’) + real ‘royal’.