ETYM Latin, from duo two + plicare to fold. Related to Two, and Complex.
1. (Telecommunication) Allowing communication in opposite directions simultaneously.
2. (Used technically of a device or process) Having two parts.
Pertaining to simultaneous two-way independent data communication transmission in both direction. Same as full duplex.
Capable of carrying information in both directions over a communications channel. A system is full-duplex if it can carry information in both directions at once; it is half-duplex if it can carry information in only one direction at a time.