Bittersweet meaning : Solanum dulcamara. Bittersweetness. A vine, of the genus Celastrus, having small orange fruit that open to reveal red seeds. A variety of apple with a bittersweet taste. Any variety of clam in the family Glycymerididae A pinkish-orange color. Any color in between scarlet and orange. Both bitter and sweet. Expressing contrasting emotions of pain and pleasure. Of bittersweet color.