What does retardant mean?
A retardant is a substance that slows, delays, or inhibits a process. Its best-known application is as a flame retardant: a material added to fabrics, plastics, furniture, electrical components, and other products to reduce their tendency to ignite or to slow the spread of fire. Retardants also have specialised industrial uses, including delaying the hardening of concrete, extending the working time of chemical mixtures, and stabilising materials during processing. The appropriate substance and quantity depend on the process involved, and some retardants may present environmental or health risks when misused or present in high concentrations. The word is generally neutral in technical contexts, although the unrelated historical use of “retarded” as an offensive description of intellectual disability has made the related vocabulary sensitive. In its material and chemical senses, “retardant” is precise and remains common in safety standards, manufacturing, and fire-safety literature.
A substance or material that slows, delays, or inhibits a process, especially combustion.
"The wood was treated with a fire retardant before being used in the theatre set."
Common collocations include “flame retardant” and “fire retardant.”
Serving to slow, delay, or inhibit a process, especially combustion.
"The paint contains a retardant additive that makes it less flammable."
The adjectival use is less common than the noun and is especially associated with technical and industrial contexts.
The plural is used when referring to different substances, materials, or agents that delay or inhibit a process.
"Different flame retardants are used in furniture foam and electrical enclosures."
Flame retardants can buy crucial seconds by slowing the spread of fire, although some retardant chemicals have raised environmental and health concerns.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does retardant come from?
The word was formed in English by adding the suffix “-ant” to “retard,” producing a noun or agent that causes delay. “Retard” comes through French from Latin “retardare,” a derivative of “tardus,” meaning slow or late. The same Latin root also underlies English words such as “tardy” and “tardigrade.”
Related word forms
How retardant is actually used
The term is chiefly technical or industrial. “Flame retardant” and “fire retardant” are its most common established uses. When describing people, use “retarded” only in formal, historical, or medical contexts where its potentially offensive sense is unavoidable.
Easily confused with retardant
A retardant is a substance that delays a process, whereas the adjective “retarded” is now avoided when describing a person because it can be considered offensive.