A genus of plants of the family Lamiaceae (Labiatae), typically with a white cottony down, which occur chiefly in the eastern Mediterranean and western Asia; (also marrubium) a plant of this genus, especially white horehound, M. vulgare. Also: a preparation of white horehound, used in some traditional cough remedies; a bitter constituent of this plant (perhaps marrubiin).
Valid publication of the genus name: Linnaeus Species Plantarum (1753) II. 582, after J. Pitton de Tournefort Inst. Rei Herbariae (1700) I. 192.
Old English; earliest use found in Pseudo-Apuleius' Herbarium. From classical Latin marrubium (also marruuium), of uncertain origin, perhaps connected with Hebrew mar ‘bitter’ or a Semitic cognate.