simplex

/ˌsɪmˈplɛks/

Definitions of simplex

1. adjective

   having only one part or element
   “a simplex word has no affixes and is not part of a compound--like `boy' compared with `boyish' or `house' compared with `houseboat'”

   synonyms:

   simple

   having few parts; not complex or complicated or involved
2. adjective

   allowing communication in only one direction at a time, or in telegraphy allowing only one message over a line at a time
   “simplex system”

   synonyms:

   unidirectional

   operating or moving or allowing movement in one direction only