What does olefin mean?
An olefin is an organic compound, specifically a hydrocarbon, whose molecular structure contains at least one carbon–carbon double bond. The best-known example is ethylene, the simplest member of the class; larger olefins include propene and butenes. The term is closely associated with “alkene,” the systematic name for this family of unsaturated hydrocarbons, and the two words are often used interchangeably. “Olefin” is especially common in petrochemical, plastics, and industrial contexts, where chemists discuss olefin production, polymerization, and the olefin content of refinery streams. These compounds are valuable because their double bonds can undergo addition reactions and, under suitable conditions, form long polymer chains. The resulting materials include polyethylene and polypropylene, which are used for packaging, containers, fibers, and many other products. Although often grouped with other hydrocarbons such as alkanes and alkynes, olefins are distinguished by the reactive double bond in their molecular framework. The word is therefore primarily scientific rather than general-purpose, but understanding it connects fundamental organic chemistry with widely used manufactured materials.
nounAn olefin is an organic compound whose molecules contain a carbon–carbon double bond. In general chemistry, the term is often used interchangeably with “alkene,” although “olefin” is especially common in industrial and petrochemical contexts.
- A hydrocarbon containing at least one carbon–carbon double bond.
- A compound regarded as a member of the alkene family, especially in petrochemical and polymer science.
"The plant uses a mixture of olefins as feedstocks for producing polymers."
"Ethylene is the simplest olefin, consisting of two carbon atoms joined by a double bond."
"Engineers are developing lower-carbon olefins as feedstocks for recyclable plastics."
The regular plural adds -s; the unmodified singular is normally used before a noun, as in “olefin production.”
"Several olefins were identified in the refinery's product stream."
From polyethylene shopping bags to pharmaceutical compounds, olefins are among the most versatile carbon skeletons in modern chemistry.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does olefin come from?
The word “olefin” developed from “ethylene,” with the longer name suggesting the related class of unsaturated hydrocarbons. “Ethylene” was itself formed from “ether,” together with the Greek suffix -ylene, and was originally associated with illuminating gas and certain ethers. The wider word family also includes related forms such as “oleic” and “oleate,” although the modern chemical meaning of “olefin” is governed specifically by the carbon–carbon double bond.
Related word forms
How olefin is actually used
The term is technical but standard in chemistry. “Alkene” is preferred in many introductory textbooks, while “olefin” is particularly frequent in industrial chemistry, petroleum refining, and polymer manufacturing. In informal or general writing, the two terms are often treated as interchangeable.
Easily confused with olefin
Alkene is the systematic class name for hydrocarbons containing a carbon–carbon double bond, while olefin is a closely related term often used in industrial chemistry and sometimes as a synonym.
Olefin names a class of unsaturated hydrocarbons, whereas oleic is an adjective meaning “of or relating to oleic acid,” the principal fatty acid found in olive oil and many other fats.