Gas

Gas is a state of matter, like a liquid or solid, where particles move freely and spread out to fill any space. In everyday use, “gas” often means gasoline used as fuel for cars, especially in American English.

“Gas” was coined in the 17th century by chemist Jan Baptista van Helmont, probably from Greek “chaos,” meaning “void” or “empty space.” He created the word to describe substances like air that weren’t solid or liquid.