表达思想和观点
1. （告别用语）再见
You say 'Goodbye' to someone when you or they are leaving, or at the end of a telephone conversation.
2. 告别语；道别；再见
When you say your goodbyes, you say something such as 'Goodbye' when you leave.
3. 道别/ 挥手告别
When you say goodbye to someone, you say something such as 'Goodbye', 'Bye', or 'See you', when you or they are leaving. You can also wave goodbye to someone.
4. 向…说再见；承认不会（或不再）拥有
If you say goodbye or wave goodbye to something that you want or usually have, you accept that you are not going to have it.
5. to kiss something goodbye - see kiss