Meaning of apartment

a•part•ment

1. a room or a group of related rooms, among similar sets in one building, designed for use as a dwelling.
2. a building containing or made up of such rooms.
3. any separated room or group of rooms in a house or other dwelling: We heard cries from an apartment at the back of the house.
4. a set of rooms used as a dwelling by one person or one family.