(1) an almost obscelete form of greeting most associated with straightlaced people;
(2) a polite way of answering a phone
(1)Bob (sees Bill on street): "Hello, Bill!"
Bill: "Well, hello, Bob."
(2)(Phone rings loudly)
James Watson from AT&T: "Hi, this is James Watson from AT&T. I'm calling to talk to you about your long distance plan."