int.

1. （用以打招呼或唤起注意）喂，你好
   Hello, Jim! How are you?

   哈罗，吉姆！你好吗？

2. （用作打电话时的招呼语）喂
3. （表示惊讶等）嘿；啊

n.

1. 表示问候（或惊奇，或唤起注意时）的叫声[C][U]
   She said hello to me when she saw me.

   她见到我时向我打招呼。

vi.

1. 喊“喂”

vt.

1. 向……说“喂”

exclam.

1. used as a greeting or to begin a telephone conversation.
2. Brit. used to express surprise or as a cry to attract someone's attention.
   ▸used informally to express sarcasm or anger.