When some person waives his right-of-way at a four-way stop by waving at the other driver to go ahead.
Jim: "Look at that idiot; he has the right-of-way, but he's waving at me to go ahead."
Bob: "He's just being polite."
Jim: "He's not being polite. He's probably so stupid he doesn't know he has the right-of-way! He is a a stop sign waiver."