retrodirective

[re-troh-di-rek-tiv, -dahy-]

adjective Optics.

(of a mirror, reflector, etc.) having three reflecting surfaces so oriented that a ray of light is reflected in a direction parallel but opposite to its original direction.

Origin of retrodirective

retro- + directive

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018