formaldehyde

American  

[fawr-mal-duh-hahyd, fer-] / fɔrˈmæl dəˌhaɪd, fər- /

noun

Chemistry.

1. a colorless, toxic, potentially carcinogenic, water-soluble gas, CH 2 O, having a suffocating odor, usually derived from methyl alcohol by oxidation: used chiefly in aqueous solution, as a disinfectant and preservative, and in the manufacture of various resins and plastics.

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formaldehyde British  

/ fɔːˈmældɪˌhaɪd /

noun

1. Systematic name: methanal.  a colourless poisonous irritating gas with a pungent characteristic odour, made by the oxidation of methanol and used as formalin and in the manufacture of synthetic resins. Formula: HCHO

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formaldehyde Scientific  

/ fôr-măl′də-hīd′ /

1. A colorless gas having a sharp, suffocating odor. It is used in making plastics and, when dissolved in a solution of water and methanol, to preserve biological specimens. Chemical formula: CH ₂ O.

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Etymology

Origin of formaldehyde

1870–75; form(ic) + aldehyde; modeled on German Formaldehyd

Compare meaning

How does formaldehyde compare to similar and commonly confused words? Explore the most common comparisons:

• paraformaldehyde vs. formaldehyde

Explanation

No, formaldehyde is not a formal hiding place. Formaldehyde is a strong-smelling colorless gas. Depending on what other elements are combined with it, formaldehyde is used for embalming, manufacturing, and all kinds of other things. Formaldehyde is really good at helping things stick together, which is why it's often used in making things like particleboard and some insulation materials found in buildings. It’s also found in some glues and paints. Besides helping things stick, formaldehyde is famous in science labs for preserving biological specimens, like animals and plants, so that they can be studied without decaying.

Example Sentences

The unusually high formaldehyde levels detected by satellites served as evidence that methane breakdown was taking place.

From Science Daily • May 10, 2026

Composite wood products can be bound with formaldehyde.

From BBC • Mar. 16, 2026

Preserved in formaldehyde and paraffin wax, they come from patients treated at the UK's national bowel hospital, St Mark's, in northwest London.

From Barron's • Feb. 4, 2026

Others include multiple types of exposures associated with fume events: chemicals that appear in both pesticides and engine oils; high levels of ultrafine particles and solvents like formaldehyde; and brain trauma.

From The Wall Street Journal • Dec. 22, 2025

With no time for embalming, they brush the dead with formaldehyde from buckets.

From "Out of Darkness" by Ashley Hope Pérez

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