Bittersweet

Part of speech: noun (n.)

1. Anything which is bittersweet.

2. A kind of apple so called. Gower.

3. 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.

4. 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.

Part of speech: adjective (a.)

Sweet and then bitter or bitter and then sweet; esp. sweet with a bitter after taste; hence (Fig.), pleasant but painful.