1. Bitter and sweet at the same time: bittersweet chocolate.

2. Producing or expressing a mixture of pain and pleasure: a movie with a bittersweet ending.

3. Dark to deep reddish-orange.

1. Any of various woody vines of the genus Celastrus, especially C. scandens, native to North America, and C. orbiculata, an eastern Asian species that is widespread in North America, having small, round, yellow-orange fruits that open at maturity to expose red seeds. Also called staff tree, staff vine.

2. See bittersweet nightshade.

3. A dark to deep reddish orange.