runaway
adj. B2 Upper Intermediate US //ˈɹənəˌweɪ// UK //ɹˈʌnəwˌeɪ// run·away
adj. describing something that is increasing or improving very quickly and cannot be stopped. You use it for trends, successes, or problems that are growing fast.
adj. characterized by rapid, unchecked growth or success; often used attributively before a noun to describe a trend, victory, or problem that is expanding quickly and uncontrollably.
The new app is a runaway success.
The company became a runaway leader in the electric vehicle market after its latest launch.
The candidate's runaway victory in the primary election signaled a decisive shift in the party's direction.
Deverbal from run away.
Usage
Typically used attributively before a noun (e.g., 'runaway success', 'runaway inflation').