The word “gas” has two completely different origin stories depending on which “gas” you mean. If you’re wondering why we call fuel “gas” even though it’s a liquid, the answer is that “gas” is just a shortened version of “gasoline,” which Americans have been using since 1897. But if you’re wondering where the word “gas” came from in the first place, that story starts with a 17th-century chemist, a Greek word for emptiness, and the Dutch pronunciation of the letter G.
The Word “Gas” Was Invented in the 1600s
Before the 1600s, there was no word for what we now call a gas. Air was just air, and anything vapor-like was lumped in with smoke or steam. That changed with Jan Baptist van Helmont, a Flemish chemist born in Brussels in 1579, who realized he was dealing with a substance that didn’t behave like a solid, liquid, or even ordinary air. When he burned charcoal or fermented wine, something invisible was released that couldn’t be captured or contained the same way as other materials. He needed a name for it.
Van Helmont based his new word on the ancient Greek word “chaos” (χάος), which described the formless void that existed before creation. In his Latin writings, he explained: “I have called that vapor Gas, not far removed from the Chaos of the ancients.” The connection between “chaos” and “gas” might seem like a stretch in English, but it makes perfect sense in Dutch. The Dutch G is pronounced as a throaty spirant sound, very close to the Greek letter chi (χ) at the start of “chaos.” So when Van Helmont wrote “gas,” he was essentially writing “chaos” the way a Dutch speaker would say it.
The specific substance Van Helmont was studying when he coined the term was what he called “gas sylvestre,” which we now know as carbon dioxide. He isolated it from fermenting wine, though he didn’t fully distinguish it from other gases like carbon monoxide. Some scholars also note that the word may have been influenced by “Geist,” the German and Dutch word for spirit or ghost, which fits neatly with the idea of an invisible, almost supernatural substance escaping from burning materials.
Why Fuel Is Called “Gas” When It’s a Liquid
Calling a liquid fuel “gas” is an American habit that confuses people outside the U.S., and reasonably so. The explanation is simple: “gas” is short for “gasoline,” and Americans started using the abbreviation so early (by 1897) that it stuck permanently.
The word “gasoline” itself appeared in the 1860s, built from “gas” plus the Latin-derived suffix “-ol” (from “oleum,” meaning oil) and the chemical ending “-ine.” At the time, “gas” was being used loosely to describe any compound of gases used for lighting and heating, so naming a new petroleum distillate after it made commercial sense. The full word “gasoline” first showed up in British English around 1863 as a trade name, then crossed to the United States, where it became the standard term for the fuel.
A Trademark Dispute Shaped the Name
The path from petroleum to “gasoline” involves a surprisingly entertaining legal fight in 1860s Dublin. In 1862, a British merchant named John Cassell began selling a clean-burning lamp oil under the trademarked name “Cazeline.” Business was good until Cassell noticed his Dublin sales dropping. When he investigated, he discovered that a local merchant named Samuel Boyd was selling counterfeit Cazeline oil. Boyd’s trick was crude but effective: he took Cassell’s packaging and changed the “C” to a “G” with a single pen stroke, creating “Gazeline.”
Cassell sued. Boyd claimed his name “Gazoline” was inspired by “gazogene,” a French device for making carbonated water, and that any resemblance to Cazeline was coincidental. The judge ordered Boyd to stop selling oil under the Cazeline name but notably did not prevent him from using “Gazoline.” The name survived, evolved into “gasoline,” and entered common use on both sides of the Atlantic just as the automobile was about to make petroleum fuel a household product.
Why Americans Say “Gas” and the British Say “Petrol”
The U.S. and the U.K. simply adopted different trade names from the same era. Americans latched onto “gasoline” and shortened it to “gas.” The British gravitated toward “petrol,” derived more directly from “petroleum.” Both words were circulating in the late 1800s, and each country settled on its own preference the way English-speaking countries often do with competing terms (think “trunk” versus “boot,” or “apartment” versus “flat”).
The result is that “gas” in American English does double duty. Context almost always makes the meaning clear: “gas station” obviously refers to fuel, while “gas stove” could mean either natural gas or propane. The ambiguity rarely causes real confusion in practice, but it does make for a genuinely interesting linguistic question, one that traces back through Irish courtrooms, Dutch pronunciation, and a 17th-century chemist staring at the invisible something escaping from a vat of fermenting wine.