Definition of chemical in English:

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Pronunciation: /ˈkɛmɪk(ə)l/


1Relating to chemistry, or the interactions of substances as studied in chemistry: the chemical composition of the atmosphere
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  • The third atom can detach from the ozone molecule and reattach to molecules of other substances, changing their chemical composition.
  • In its simplest terms, a chemical standard is a substance for which the exact composition is known.
  • Elements are materials that cannot be reduced to simpler substances by normal chemical means.
1.1Relating to chemicals: chemical treatments for killing fungi
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  • Just as the sweet smells of fall fill the air, the residents of the housing complex where I live are notified again - for the fourth time this year - of a chemical lawn treatment.
  • Councillors have been told that fitting water filtering and chemical treatment would cost £223,000 plus annual running costs of £45,220.
  • The hormone treatment is straightforward chemical castration - I am now impotent but it's an advantageous trade-off against a possibly fatal alternative.
1.2Relating to or denoting the use of poison gas or other chemicals as weapons of war.
Example sentences
  • The war that followed saw them employing chemical weapons and both sides firing ballistic missiles at major cities.
  • Aside from the nuclear variety of WMD, biological and chemical weapons pose serious dangers.
  • In previous wars it took large artillery bombardments to make chemical weapons effective.


1A distinct compound or substance, especially one which has been artificially prepared or purified: never mix disinfectant with other chemicals
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  • There is often more than one synthetic route for preparing a desired chemical.
  • Also, the chemical plant was processing ammonium nitrate, a stable chemical that requires a substantial infusion of energy to explode.
  • It stores and processes hundreds of tonnes of toxic and highly inflammable chemicals and compounds.
1.1An addictive drug: [as modifier]: chemical dependency
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  • Scientists continue to explore the remarkable protective effect of nicotine - the addictive chemical in tobacco - on the brain.
  • He says he has been clean from heroin for years and now takes a prescribed opiate to combat the pain, but is desperate to get off the addictive chemical.
  • It is normally protected from chemicals and drugs by the blood-brain barrier, which acts as a filter.


Late 16th century: from French chimique or modern Latin chimicus, chymicus, from medieval Latin alchymicus, from alchimia (see alchemy).

Words that rhyme with chemical

academical, agrochemical, alchemical, biochemical, petrochemical, photochemical, polemical

For editors and proofreaders

Line breaks: chem|ical

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