formaldehyde

noun

form·​al·​de·​hyde fȯr-ˈmal-də-ˌhīd 

fər-

: a colorless pungent irritating gas CH₂O used chiefly in aqueous solution as a disinfectant and preservative and in chemical synthesis

Examples of formaldehyde in a Sentence

Recent Examples on the Web

Some chemicals produced by e-cigarettes include formaldehyde and acetaldehyde, which are known to cause both lung and heart disease. —Omer Awan, Forbes.com, 1 Sep. 2025

McKinney recalled seeing reports that the trailers contained dangerous levels of the harmful chemical formaldehyde, but tried to ignore them. —Avalon Hester, People.com, 28 Aug. 2025

It is designed to remove a significant amount of pollutants, including dust, pollen, bacteria, and formaldehyde. —Matt Emma, USA Today, 22 Aug. 2025

Gas turbines release smog-forming pollution and hazardous chemicals like formaldehyde—which are tied to increases in asthma, respiratory diseases, heart problems, and certain cancers. —Andrew R. Chow, Time, 13 Aug. 2025

Word History

Etymology

International Scientific Vocabulary form- + aldehyde

First Known Use

1872, in the meaning defined above

Phrases Containing formaldehyde

• urea-formaldehyde

Rhymes for formaldehyde

• acetamide
• acetonide
• acidified
• antimonide
• beatified
• benzaldehyde
• borohydride
• chalcogenide
• commodified
• decalcified
• declassified
• disaccharide

Kids Definition

formaldehyde

noun

form·​al·​de·​hyde fȯr-ˈmal-də-ˌhīd 

fər-

: a colorless gas that consists of carbon, hydrogen, and oxygen, has a sharp irritating odor, and when dissolved in water is used to disinfect or to prevent decay

Medical Definition

formaldehyde

noun

form·​al·​de·​hyde fȯr-ˈmal-də-ˌhīd, fər- 

: a colorless pungent irritating gas CH₂O used chiefly as a disinfectant and preservative and in chemical synthesis