Complex of lines Meaning, Definition & Usage

Definitions
  1. (Geom.), all the possible straight lines in space being considered, the entire system of lines which satisfy a single relation constitute a complex; as, all the lines which meet a given curve make up a complex. The lines which satisfy two relations constitute a congruency of lines; as, the entire system of lines, each one of which meets two given surfaces, is a congruency.

Webster 1913