An Entryphone is the little phone or speaker by the street door of a building. A visitor presses a button, talks to someone inside, and that person can open the door without coming down. The name is a trademark, held by The Entryphone Company Limited, but in British English many people still say entryphone for the machine itself — the way some people say hoover for any vacuum cleaner. In other places the everyday words are intercom, door phone, or buzzer. It is not a normal telephone for calling friends; it only joins the door to the people inside.