Also,
good afternoon or evening or morning . Formal ways of saying "Hello" or "Goodbye." For example,
He began rather oddly by addressing the audience with "
Good day," or "
Good afternoon, ladies,"
said the sales clerk as we walked out. All these greetings represent an abbreviation of the now obsolete
God give you a good day (afternoon, etc.), which dates from about 1200. Also see
good night.