• synonyms


  1. the branch of chemistry that deals with the chemical action of light.
Show More

Origin of photochemistry

First recorded in 1865–70; photo- + chemistry
Related formspho·to·chem·i·cal [foh-toh-kem-i-kuh l] /ˌfoʊ toʊˈkɛm ɪ kəl/, pho·to·chem·ic, adjectivepho·to·chem·i·cal·ly, adverbpho·to·chem·ist, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for photochemical

Historical Examples

  • Scheele's work aroused much interest in photochemical effects and many investigations followed.

    Artificial Light

    M. Luckiesh

  • The foregoing are only a few of the multitude of photochemical reactions and other effects of radiant energy.

    Artificial Light

    M. Luckiesh

  • We must therefore conclude that the heliotropic curvature of the polyps is determined by a photochemical action of the light.

  • The product of photochemical decomposition no longer forms azo-colours with amines or phenols.


    Raphael Meldola

British Dictionary definitions for photochemical


  1. of or relating to photochemistry; involving the chemical effects of light
Show More
Derived Formsphotochemically, adverb


  1. the branch of chemistry concerned with the chemical effects of light and other electromagnetic radiationsAlso called: actinochemistry
Show More
Derived Formsphotochemist, noun
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

photochemical in Medicine


  1. The branch of chemistry that deals with the effects of light on chemical systems.
Show More
Related formspho′to•chemi•cal (-ĭ-kəl) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

photochemical in Science


  1. The scientific study of the effects of light and ultraviolet radiation on chemical reactions.
Show More
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.