Try Our Apps


Pore Over vs. Pour Over


[al-fuh-naf-thawl, -thol, -nap-] /ˌæl fəˈnæf θɔl, -θɒl, -ˈnæp-/
noun, Chemistry
See under naphthol.


[naf-thawl, -thol, nap-] /ˈnæf θɔl, -θɒl, ˈnæp-/
noun, Chemistry
either of two isomeric hydroxyl derivatives, C 1 0 H 7 OH, 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.
Also called hydroxynaphthalene.
Origin of naphthol
1840-50; naphth- + -ol1 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the Web for alpha-naphthol
Historical Examples
  • alpha-naphthol for dark reds from Primuline, greys from Diamine blues, Neutral grey, etc.

  • Practically the only phenol that is used is the beta-naphthol; alpha-naphthol is occasionally used, but not often.

British Dictionary definitions for alpha-naphthol


/ˈnæfθɒl; ˈnæp-/
a white crystalline solid having two isomeric forms, alpha-naphthol, used in dyes, and beta-naphthol, used in dyes and as an antioxidant. Formula: C10H7OH
Word Origin
C19: from naphtha + -ol1
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
Cite This Source
alpha-naphthol in Medicine

naphthol naph·thol (nāf'thôl', -thōl', nāp'-) or naph·tol (-tôl, -tōl)
An organic compound occurring in two isomeric forms, alpha-naphthol and beta-naphthol. Also called naphthalenol.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
alpha-naphthol in Science
  (nāf'thôl', -thōl', nāp'-)   
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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for alpha-naphthol

Few English speakers likely know this word

Word Value for alpha

Scrabble Words With Friends