インターフォン
インターフォン · intaafuォn · JLPT N1 · noun
telephone
📞 インター (inter-, between) + フォン (phone) = a phone between two places, like a door to flat
インター is short for intercommunication, from inter- meaning between, and フォン is the borrowed word phone. Together they name the phone linking a building entrance to a unit inside.