Pen`ny*roy"al (?), n. [A corruption of OE. puliall royal. OE. puliall is ultimately derived fr. L. puleium, or pulegium regium (so called as being good against fleas), fr. pulex a flea; and royal is a translation of L. regium, in puleium regium.] Bot.
An aromatic herb (Mentha Pulegium) of Europe; also, a North American plant (Hedeoma pulegioides) resembling it in flavor.
Bastard pennyroyal Bot. See Blue curls, under Blue.
© Webster 1913.