potential

This is one of those words that looks abstract and bloodless, but its ancestry is all muscle. Latin had potis, meaning “able” or “powerful,” and from that came potens — the ancestor not just of potential, but of potent, potency, possible, and even plenipotentiary, the grand diplomatic title that sounds like someone with a wax seal and a very large hat. Romans were already treating power as something you could have in reserve, like a weapon in a scabbard; by the late 1300s English borrowed the idea as potential, meaning “possible, but not yet real.” Then in 1817 Coleridge gave the adjective a nouny afterlife, so now potential can mean the hidden force inside a person, a machine, or a physics equation. It’s a nice little linguistic trap: the word for unrealized ability began life meaning plain old ability.