simplex
Concise Oxford English Dictionary © 2008 Oxford University Press:
simplex/ˈsɪmpleks/
▶adjective technical
- 1 composed of or characterized by a single part or structure.
- 2 (of a communication system, computer circuit, etc.) only allowing transmission of signals in one direction at a time.
– origin C16: from L., lit. ‘single’, var. of simplus ‘simple’.
'simplex' also found in these Oxford entries:

