a.

1. 怀着希望的；乐观的[（+about/of）]
   His private expectations were not so sanguine.

   他私下的期望并不是那么乐观。

2. 血色好的，红润的
3. 血红的
4. 【罕】嗜血成性的，血腥的

adj.

1. cheerfully optimistic.
2. (in medieval medicine) having a predominance of blood among the bodily humours, supposedly marked by a ruddy complexion and an optimistic disposition.
   ▸archaic (of the complexion) ruddy.
3. archaic bloody or bloodthirsty.
4. literary & Heraldry  blood-red.

n.