Is the word "idiot" Greek?
Is the word "party" greek?
The word "οικία" (house in ancient greek), is it used in modern greek too?
The word "οικία" is ancient Greek and means "house". In modern Greek it is often the second part of compound words, for example "κατοικία" (residence), "συνοικία" (neighborhood).
In some formal documents we may find expressions like "τηλέφωνο οικίας" (home telephone number) or "διεύθυνση οικίας" (home address).