runaway

runaway — adjective

1. describes a person or an animal that has escaped from a place where they were be

1.adjectiveB1
Definition

describes a person or an animal that has escaped from a place where they were being kept or supervised

Example

Police caught the runaway inmates near the river three hours later.

attributive before noun (person)

A runaway horse was seen galloping along the highway yesterday morning.

attributive before noun (animal)

Common collocations
  • runaway teenager
  • runaway horse
  • runaway prisoner
  • runaway slave
Synonyms
  • escaped

    neutral, used broadly for people and animals who have gotten free

  • fugitive

    stronger connotation of being pursued by law, used mainly for people

Antonyms
  • captive

    someone or something that is confined or held in place

  • contained

    kept within bounds or under control

Grammar Patterns

runaway + noun (person/animal)

Usage Note

Attributive only — do not use after a linking verb (❌ The horse was runaway).

Common Mistakes

The cat was runaway from the house.
The cat was a runaway from the house.
'runaway' as an adjective cannot follow a linking verb; use the noun form instead.
A run away dog was found in the park.
A runaway dog was found in the park.
'runaway' is one word when used as an adjective.

2. describes a vehicle, machine, or process that has become impossible to control o

2.adjectiveB1
Definition

describes a vehicle, machine, or process that has become impossible to control or stop

Example

A runaway truck crashed through the safety barrier on the mountain road.

attributive before noun (vehicle)

The factory shut down after a runaway chemical reaction in the lab.

Common collocations
  • runaway truck
  • runaway train
  • runaway inflation
  • runaway reaction
  • runaway costs
Synonyms
  • out-of-control

    more general, can be used predicatively (the car was out of control)

  • uncontrollable

    emphasises the inability to manage the situation

Antonyms

Grammar Patterns

runaway + noun (vehicle/process/economic force)

Usage Note

Attributive only. Also used figuratively for events or processes that move too quickly to manage (runaway inflation, runaway costs).

Common Mistakes

The car was runaway on the highway.
The car went out of control on the highway.
do not use 'runaway' after a linking verb; use 'out of control' instead.

3. describes a product, show, or business that becomes extremely and surprisingly s

3.adjectiveB2
Definition

describes a product, show, or business that becomes extremely and surprisingly successful in a very short time

Example

The small bakery became a runaway success within three months of opening.

attributive before 'success'

Her debut novel was a runaway best-seller in twelve different countries.

Common collocations
  • runaway success
  • runaway hit
  • runaway best-seller
  • runaway winner
Synonyms
  • sensational

    informal, emphasises how exciting or impressive the success is

  • meteoric

    describes a rise or success that happens very fast, like a meteor shooting across the sky

Antonyms

Grammar Patterns

runaway + success / hit / best-seller

Usage Note

Attributive only. Almost always appears before success, hit, or best-seller. The surprise element is central — it is not used for expected achievements.

Common Mistakes

The movie was runaway popular.
The movie was a runaway hit.
'runaway' modifies success/hit/best-seller, not adjectives like 'popular'.
He had a runaway career.
His first book was a runaway success.
'runaway' is not a general intensifier; it pairs with specific nouns.

runaway — noun

runaway — verb

Word family

Synonym discussion

Sense: adjective/2

Runaway (adjective) specifically describes a thing that has already broken free from control — a runaway train, runaway inflation. Out-of-control is the broadest and most neutral term, usable both attributively and predicatively: 'The fire was out of control.' Uncontrollable emphasises the inherent difficulty of managing something, even before it breaks loose: 'an uncontrollable urge to laugh.' Rampant is reserved for negative phenomena that spread unchecked, typically in abstract domains: 'rampant corruption' or 'rampant disease.' Choose runaway when the key idea is that control was lost despite efforts to keep it; choose uncontrollable when the focus is on the impossibility of control from the start.

runawayout-of-controluncontrollablerampant

Common collocations

Phrases

  • run away from home
  • run away from danger
  • a runaway success

Prepositions

Etymology

Old EnglishMiddle EnglishModern English

Formed by combining the verb 'run' (from Old English 'rinnan', meaning to move quickly on foot) and 'away' (from Old English 'on weg', meaning from this place). The two words merged over time into a single compound. The earliest recorded uses of 'runaway' as a noun date from the 1400s (a person who runs away). By the 1700s it was used as an adjective for escaped animals. The 'out of control' meaning for vehicles emerged in the 1800s alongside the rise of trains and machinery, and the 'huge success' sense appeared in the 1900s, originally in theatre reviews describing a play that drew far larger audiences than expected.