Naphthol AS

noun

1

: a crystalline phenolic anilide HOC₁₀H₆CONHC₆H₅ used as a coupling component for azoic dyes; the anilide of 3-hydroxy-2-naphthoic acid

2

: any of a series of arylides of either ortho -hydroxy aromatic carboxylic acids (as 3-hydroxy-2-naphthoic acid) or acyl derivatives (as acetoacetic acid) of acetic acid used as coupling components for azoic dyes

Word History

Etymology

German naphthol AS, from naphthol + AS, from anilid anilide + säure acid

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