quadruplex

adj

1. (not-comparable)Having four components.
2. (not-comparable)Of or relating to a system in telegraphy by which four messages (two in each direction) can be sent on one wire simultaneously.
3. (not-comparable)Of or relating to an early videotape format with four magnetic record/reproduce heads mounted on a headwheel spinning transversely across the tape.

noun

1. (countable)A quadruplex system.

   “The Western Union office is equipped with four quadruplexes, three duplexes and eleven single loops, besides special private loops in the Japanese and Russian suites, where direct communication will be maintained with the Atlantic cables at Heart’s Content, Newfoundland via Canso, and also with the Western Union offices in New York, whence the Japanese diplomatic matter will be sent via land lines to San Francisco over a direct circuit.”

2. (abbreviation, alt-of, clipping, uncountable)Clipping of quadruplex videotape, an early type of videotape with four magnetic record/reproduce heads mounted on a headwheel spinning transversely across the tape.

verb

1. (transitive)To make quadruplex.