1. To take place or to occur; especially, without being planned: That kind of accident will happen when driving as fast as Steve usually does.

Mother asked, "Jimmy, what happened at school today? Did you happen to learn anything?"

2. To do or to be something by accident or by chance: Adele happened to overhear the doctor and the nurse talking about her accident.
3. Used to express an angry or forceful statement: Jack said, "Well, Bonita, Louis happens to believe that the politician has been a lousy representative for our district!"