an electronic special-effects system for combining a desired background with live foreground action.
Origin of chroma key
First recorded in 1970–75
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
(in colour television) a special effect in which a coloured background can be eliminated and a different background substitutedAlso called: colour separation overlay
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012