noun
Usage: often capitalized F&S
: an orange-red crystalline amine CH 3 OC 6 H 3 (NO 2 )NH 2 that is often sold in the form of its stabilized diazonium complex salt with zinc chloride and is used in producing azoic dyes; 4-nitro- ortho -anisidine — see dye table I (under Azoic Diazo 13 )