runaway

A "runaway" can be a person who has left home or another place without permission, especially a child or teenager. It can also describe something that is out of control and hard to stop, like a train, a horse, or inflation that keeps rising too fast. In another common use, it describes a very easy win or a big success that pulls far ahead of the rest. The word usually carries a sense of speed, urgency, or loss of control.

"Runaway" has several connected meanings, and they all center on the idea of getting free, moving beyond control, or pulling far ahead. In older writing, it was often used for people escaping bondage or captivity. That history still gives the word some weight in certain contexts.

In modern English, "runaway" is mainly a noun or an adjective. As a noun, it usually means a person, often a young person, who leaves home or care without permission: "The police are searching for the runaway teenager." As an adjective, it can describe something moving on its own and out of control, as in "a runaway train," or something growing too fast to manage, as in "runaway inflation." It can also describe a result that is not even close, such as "a runaway victory" or "a runaway bestseller," where one person, team, or thing clearly pulls ahead.

The single word "runaway" comes from the phrasal verb "run away," which means to flee or escape. "He ran away from the bullies." But the one-word form is not used in the same way. You would say "a runaway child" or "runaway costs," not "he runaway."

Overall, the word suggests that something has slipped free of normal limits. Sometimes that idea is literal, sometimes it is about rising numbers, and sometimes it is about a contest that is no longer close. Whether it points to a missing child, a train that cannot be stopped, or a clear first-place finish, "runaway" brings a strong feeling of motion, urgency, and lost control.