Olefiant

Part of speech: adjective

Definitions

1. A hydrocarbon containing at least one carbon-carbon double bond, also known as an unsaturated hydrocarbon capable of combining with other substances through addition reactions
2. A type of unsaturated hydrocarbon characterized by the presence of one or more double bonds between carbon atoms, which allows it to engage in various chemical reactions
3. An unsaturated hydrocarbon that features at least one carbon-carbon double bond, enabling its participation in addition reactions with other chemical compounds

Etymology: "Olefiant" is a technical coinage from chemistry, not an old word with a long road into English. It comes from French "gaz oléfiant," literally "oil-making gas." The French phrase joins "olé," from Latin "oleum" meaning "oil," with "-fiant," the "producing" element from "-fier," meaning "to make or produce," which is the same suffix behind words like "fortify" and "vivify" in English. The name arose because the gas that chemists first made in the eighteenth century, by treating alcohol with sulphuric acid, produced a dense, oily liquid when it was combined with chlorine. The gas was thus said to produce oil, giving the name "oil-former" to the whole group of compounds with a double bond between two carbon atoms, now called alkenes. The English adjective keeps the French form, a reminder that chemical vocabulary of this period was largely built in French.