a.

1. 惡意的，陰險的，邪惡的
   a sinister smile

   奸笑

   A sinister expression appeared on his face when I called him a liar.

   當我稱他為騙子時，他的臉上出現了一個凶惡的表情。

2. 凶兆的，不祥的
3. 不幸的，災難性的
   a sinister fate

   厄運

4. 左邊的；在左邊的[Z]

adj.

1. suggestive of evil or harm.
2. archaic & Heraldry  on or towards the left-hand side (in a coat of arms, from the bearer's point of view, i.e. the right as it is depicted). The opposite of dexter¹.