vi.

1. 變黑；變暗

vt.

1. 使變黑；使變暗
   The commandos blackened their faces with charcoal.

   突擊隊員用木炭把臉塗黑。

2. 敗壞（名譽等）；詆毀
   Don't blacken my name by spreading rumors.

   不要散播流言，破壞我的名譽。

v.

1. become or make black or dark.
2. damage or destroy (someone's reputation).