# retardance

> English word · Noun

## Definitions
1. The difference in phase shift between two characteristic polarizations of light upon reflection from an interface. Retardance can be reported in the Abelès or Mueller conventions. The retardance phase shift angle is often specified in degrees.

## Etymology
From Middle French retardance.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/retardance