An intercom system fitted at the entrance to a building, especially a block of flats, by which visitors can identify themselves to specific occupants before being admitted to the building
a type of telephone outside a building that allows visitors to ask someone inside to open the door
{i} (British Trademark) intercommunication system at the entrance to a building which is used by people who want to speak to a person who is inside the building or by which visitors identify themselves before the door is opened remotely