The Collaborative International Dictionary
Tartrazine \Tar"tra*zine\, n. [Tartaric + hydrazine.] (Chem.) An artificial dyestuff obtained as an orange-yellow powder, and regarded as a phenyl hydrazine derivative of tartaric and sulphonic acids.
Wiktionary
n. (context chemistry English) A lemon-yellow azo dye used as a food colouring.
Wikipedia
Tartrazine is a synthetic lemon yellow azo dye primarily used as a food coloring. It is also known as E number E102, C.I. 19140, FD&C Yellow 5, Acid Yellow 23, Food Yellow 4, and trisodium 1-(4-sulfonatophenyl)-4-(4-sulfonatophenylazo)-5-pyrazolone-3-carboxylate).
Tartrazine is a commonly used color all over the world, mainly for yellow, and can also be used with Brilliant Blue FCF (FD&C Blue 1, E133) or Green S (E142) to produce various green shades.
Usage examples of "tartrazine".
Indigo extract, Cochineal, Acid Magenta, Picric acid, Naphthol Yellow, and Tartrazine dye the wool only at the boil.