bell ringer

Short definition from Wiktionary

Noun

1. 1
   A person, especially one of a group, who rings bells.
2. 2
   A door-to-door salesman.
3. 3
   An assignment, done regularly at the beginning of a class, and intended as a warm-up before other classroom activities.
4. 4
   A type of anatomy exam in which students must answer questions at a series of stations and move on to the next station when a bell is rung.
5. 5
   Alternative spelling of bell ringer.