The leftover foundation thats stuck on your screen after a conversation where the phone has been pressed against the cheek. Often seen on touch phones, since they have a larger screen.
Emma: EEEEUUUW! Whats that brown gunk on your screen?!
Johanna: Aaah, thats just some phonedation after my conversation with Peter.
Tired of chatting with his gf Annie on MSN, Billy decided to be a man and have a phonversation with Annie.
MSN
Annie: Why won't you ever have a phonversation with me?
Billy: Your voice makes me want to throw up. You sound prettier when I can make up a voice in my head for you.
Annie:...we're through.