bittersweet

Short definition from Wiktionary

Adjective

1. 1
   Both bitter and sweet.
2. 2
   Expressing contrasting emotions of pain and pleasure.
3. 3
   Of bittersweet color (see the noun section, below).

Noun

1. 1
   Bittersweet nightshade (Solanum dulcamara).
2. 2
   Bittersweetness.
3. 3
   A vine, of the genus Celastrus, having small orange fruit that open to reveal red seeds.
4. 4
   A variety of apple with a bittersweet taste.
5. 5
   Any variety of clam in the family Glycymerididae
6. 6
   A pinkish-orange color. Any color in between scarlet and orange.