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

Opponents argue that xAI understated the amount of pollution that will be emitted by its turbines in its permit application, with particular concerns around smog-forming nitrogen oxides and other pollutants that can be harmful to human health, including formaldehyde and airborne particulate matter. —Lora Kolodny, CNBC, 10 Mar. 2026

Each mattress meets strict environmental standards and is made without fiberglass, formaldehyde or heavy metals. —Tory Johnson, ABC News, 7 Mar. 2026

Contaminants include asbestos, heavy metals, lead, formaldehyde, cyanide and carcinogens. —Tony Saavedra, Daily News, 5 Mar. 2026

Relaxers and chemical straighteners, touted for their easy-to-manage outcomes, saw a decline in use as more people learned about formaldehyde, a key ingredient in relaxer products and a carcinogen. —Leah Asmelash, CNN Money, 28 Feb. 2026

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