[ naf-thuh-leen, nap- ]

  1. a white, crystalline, water-insoluble hydrocarbon, C10H8, usually obtained from coal tar: used in making dyes, as a moth repellant, etc.

Origin of naphthalene

First recorded in 1865–70; naphth- + -al3 + -ene
  • Also called tar camphor .
  • Also naph·tha·line, naph·tha·lin [naf-thuh-lin, nap-]. /ˈnæf θə lɪn, ˈnæp-/.

Other words from naphthalene

  • naph·thal·ic [naf-thal-ik, nap-], /næfˈθæl ɪk, næp-/, naph·tha·len·ic [naf-thuh-len-ik, nap-], /ˌnæf θəˈlɛn ɪk, ˌnæp-/, adjective

Words Nearby naphthalene Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use naphthalene in a sentence

  • Eighteen different facilities emit a variety of cancer-causing pollutants such as benzene, butadiene and naphthalene into the air of Port Arthur and its neighboring towns.

    The Dirty Secret of America’s Clean Dishes | by Max Blau and Lylla Younes, photography by Kathleen Flynn, special to ProPublica | December 20, 2021 | ProPublica
  • The undissolved hydrocarbon is similarly purified by fractional distillation, and furnishes the solid crystalline naphthalene.

    Coal | Raphael Meldola
  • Owing to the structure of the naphthalene molecule there are two isomeric naphthols, whereas there is only one phenol.

    Coal | Raphael Meldola
  • Secondary azo-colours derived from these bases and the usual naphthalene derivatives are also manufactured.

    Coal | Raphael Meldola
  • Other colouring-matters of the same group are in use; some of them, like “new blue,” being derivatives of naphthalene.

    Coal | Raphael Meldola
  • In addition to the azo-colours, there are certain other products which claim naphthalene as a raw material.

    Coal | Raphael Meldola

British Dictionary definitions for naphthalene


naphthaline naphthalin (ˈnæfθəlɪn, ˈnæp-)

/ (ˈnæfθəˌliːn, ˈnæp-) /

  1. a white crystalline volatile solid with a characteristic penetrating odour: an aromatic hydrocarbon used in mothballs and in the manufacture of dyes, explosives, etc. Formula: C 10 H 8

Origin of naphthalene

C19: from naphtha + alcohol + -ene

Derived forms of naphthalene

  • naphthalic (næfˈθælɪk, næp-), adjective

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

Scientific definitions for naphthalene


[ năfthə-lēn′ ]

  1. A white crystalline compound made from coal tar or petroleum and used to make dyes, mothballs, explosives, and solvents. Naphthalene consists of two benzene rings fused together. Chemical formula: C10H8.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.