vt.

1. 控告，对……提起诉讼[（+for）]
   She sued the company for racial discrimination.

   她以种族歧视为由对公司起诉。

2. 请求；要求[（+for）][O2]
   The boy sued his father for mercy.

   男孩向他父亲求饶。

3. 向……求爱，向……求婚

vi.

1. 控告，提出诉讼[（+for）]
   They sued for breach of contract.

   他们以违反合同为由提出诉讼。

2. 请求；要求[（+for/to）]
3. 求爱，求婚[（+for）]

v.

1. institute legal proceedings against (a person or institution), typically for redress.
2. formal appeal formally to a person for something.