- Twofold; double.
- Having two apartments, divisions, or floors.
- Relating to or being a single assembly of machinery having two identical units that are capable of operating simultaneously or independently.
- Electronics Of or relating to a communications mode, as in a telephone system, that provides simultaneous transmission and reception in both directions.
- A house divided into two living units or residences, usually having separate entrances.
- Something, such as an apartment, that is duplex.