Collins COBUILD Advanced Learner's English Dictionary - goodbye

also good-bye (goodbyes) 1. You say ‘Goodbye’ to someone when you or they are leaving, or at the end of a telephone conversation. CONVENTION c darkgreen]formulae 2. When you say your goodbyes, you say something such as ‘Goodbye’ when you leave. He said his goodbyes knowing that a long time would pass before he would see his child again... I said a hurried goodbye and walked home in the cold... N-COUNT: usu supp N 3. 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. He left without saying goodbye... He wanted to say goodbye to you... They came to the front door to wave goodbye. PHRASE: V inflects, oft PHR to n 4. 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. He has probably said goodbye to his last chance of Olympic gold... We can wave goodbye to the sort of protection that people at work need and deserve. PHRASE: V inflects, PHR n 5. to kiss something goodbye: see kiss