intercom
UK: ˈɪntəkɒm | US: ˈɪntərkɑːm
n. a communication system within a building or vehicle, allowing people to speak to each other via microphones and loudspeakers
The word "intercom" is a 20th-century contraction of "intercommunication." It combines the prefix "inter-" (from Latin inter, meaning "between") with the shortened form "com" (from "communication," derived from Latin communicare, "to share"). The term reflects the device's function of enabling two-way audio communication between different rooms or areas.
The office uses an intercom to announce meetings.
She pressed the intercom button to speak to the receptionist.
The pilot addressed the passengers through the aircraft's intercom.
The school installed a new intercom system for emergencies.
He heard a buzzing sound from the intercom at the front gate.