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

The three-in-one machine will tackle the usual suspects, dust and particles, but also remove formaldehyde with a carbon filter (which can be found in some carpets and furniture and cause eyes and throat irritation). —Yelena Moroz Alpert, Architectural Digest, 9 July 2025

Organic sheets leave chemicals like formaldehyde and TCEP (a flame retardant) out of your bedroom and away from your skin. —Nena Farrell, Wired News, 10 June 2025

Everything from polyurethane foams with formaldehyde and TCEP (a flame retardant) to phthalates can end up in nonorganic mattresses, off-gassing into your home. —Scott Gilbertson, Wired News, 16 June 2025

Recent research says that biofuel refiners also emit significant amounts of carcinogenic and dangerous substances, including hexane and formaldehyde, in greater amounts than petroleum refineries. —ArsTechnica, 14 June 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