any of a large class of dyes containing one or more azo groups.
Origin of azo dye
First recorded in 1880–85
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for azo dye
any of a class of artificial dyes that contain the azo group. They are usually red, brown, or yellow and are obtained from aromatic amines
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