<p><strong>Noun</strong></p><ul><li>Any of several, sometimes thorny trees or shrubs belonging to the genus <em>Rhamnus</em>, especially <em>R. frangula</em>, the bark of which is used in medicine.</li><li>A tree or shrub belonging to the genus <em>Bumelia</em>, of the sapodilla family, especially <em>B. lycioides</em>, a thorny tree having elliptic leaves and large clusters of white flowers, common in the southern and central parts of the U.S.</li></ul>