sweet and then bitter or bitter and then sweet; esp. sweet with a bitter after taste; hence (fig.), pleasant but painful.-anything which is bittersweet.-a kind of apple so called.-a climbing shrub, with oval coral-red berries (solanum dulcamara); woody nightshade. the whole plant is poisonous, and has a taste at first sweetish and then bitter. the branches are the officinal dulcamara.-an american woody climber (celastrus scandens), whose yellow capsules open late in autumn, and disclose the red aril which covers the seeds; -- also called roxbury waxwork.