naphthol

[ naf-thawl, -thol, nap- ]

/ ˈnæf θɔl, -θɒl, ˈnæp- /

noun Chemistry.

either of two isomeric hydroxyl derivatives, C10H7OH, of naphthalene (alpha-naphthol or 1-naphthol and beta-naphthol or 2-naphthol), white or yellowish crystals, with a phenolic odor, that darken on exposure to light: used chiefly in dyes, drugs, perfumes, and insecticides.

Words nearby naphthol

naphtha, naphthacene, naphthalene, naphthalize, naphthene, naphthol, naphthol yellow s, naphthyl, naphthyl group, napier, napier grass

Origin of naphthol

First recorded in 1840–50; naphth- + -ol¹

Also called hydroxynaphthalene.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for naphthol

Various additions have been made from time to time to the naphthol bath.
The Dyeing of Cotton Fabrics|Franklin Beech
The compounds formed are brilliant orange dyes, the latter being still largely consumed as “naphthol orange.”
Coal|Raphael Meldola
When this compound is combined with naphthol diazo-azo dyes are produced.
The Dyeing of Cotton Fabrics|Franklin Beech
So instead of phenol, other coal tar products such as cresol, naphthol or benzene itself may be used.
Creative Chemistry|Edwin E. Slosson

Naphthol Yellow is of course a naphthol colour, whilst Vermilline Scarlet is a dye containing both naphthylamine and naphthol.
The Chemistry of Hat Manufacturing|Watson Smith

British Dictionary definitions for naphthol

naphthol

/ (ˈnæfθɒl, ˈnæp-) /

noun

a white crystalline solid having two isomeric forms, alpha-naphthol, used in dyes, and beta-naphthol, used in dyes and as an antioxidant. Formula: C 10 H 7 OH

Word Origin for naphthol

C19: from naphtha + -ol 1

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

Medicine definitions for naphthol

naphthol

[ năf′thôl′, -thōl′, năp′- ]

n.

An organic compound occurring in two isomeric forms, alpha-naphthol and beta-naphthol.naphthalenol

Science definitions for naphthol

naphthol

[ năf′thôl′, -thōl′, năp′- ]

A poisonous organic compound occurring in two isomeric forms. Both isomers are important in the manufacture of dyes, and also in making antiseptics, insecticides, and tanning agents. Naphthol consists of a hydroxyl group (OH) attached to naphthalene. Chemical formula: C10H8O.