runaway

• run-away

run +‎ away

runaway (plural runaways)

1. A person or animal that runs away or has run away; a person, animal, or organization that escapes limitations.

   Runaway children are vulnerable to criminal exploitation.

   • Shakespeare

     Thou runaway, thou coward, art thou fled?

   • 1556, Ralph Robinson, Utopia: originally printed in Latin, 1516, translation of original by Sir Thomas More, page 96:

     If any man of his owne heade and without leaue, walke out of his precint and boundes, taken without the princes letters, he is broughte againe for a fugitiue or a runaway with great shame and rebuke, and is sharpely punished.

2. A vehicle (especially, a train) that is out of control.
   • 1850, “The Romance of the Electric Telegraph”, in New monthly magazine, volume 41:

     On New Year's Day, 1850, a catastrophe, which it is fearful to contemplate, was averted by the aid of the telegraph. A collision had occurred to an empty train at Gravesend; and the driver having leaped from his engine, the latter started alone at full speed to London. Notice was immediately given by telegraph to London and other stations; and while the line was kept clear, an engine and other arrangements were prepared as a buttress to receive the runaway.

   • 1886, John H. Cooper, “Handling Grain in California”, in Transactions, American Society of Mechanical Engineers, volume 7:

     Runaways are rendered impossible, as the machine can be instantly stopped by means of a double brake connected with the driver's seat

   • 1897, Editor American Machinist, “Runaway Engines and Governors”, in American machinist:

     We hear many ideas advanced as to the cause of engines running away, more especially in electric stations, while the wonder is that the runaways are so few.

3. (usually attributive) An object or process that is out of control or out of equilibrium.
   • 1989, Gerald Appel, Winning market systems:

     On the chart, the start of a runaway is marked by a box

   • 1993 June 15, CIO, volume 6, number 14, page 26:

     An IS executive's worst nightmare, such runaways are a fact of life. Practically all large companies and organizations have experienced a runaway or are wrestling with a seriously botched project.

   • 2000, F. Matteucci; Franco Giovannelli, The evolution of the Milky Way, page 142:

     The standard X-ray binary Cyg Xl, with a massive BH candidate, is a runaway, This could suggest that a SN explosion occurred. Cluster ejection to make a runaway can not be excluded although in the case of Cyg Xl, the progenitor runaway must have been a binary

   • 2008, Francis Stoessel, Thermal safety of chemical processes, page 257:

     Where practicable, this passive measure reduces the consequences of a runaway.

4. The act of running away, especially of a horse or teams.

   There was a runaway yesterday.

5. An overwhelming victory.

   The home side won in a runaway.

runaway (comparative more runaway, superlative most runaway)

1. having run away; escaped; fugitive

   a runaway thief

   1. (of a horse or other animal) having escaped from the control of the rider or driver

      a runaway donkey

   2. pertaining to or accomplished by running away or eloping

      a runaway marriage

2. easily won, as a contest

   a runaway victory at the polls

3. unchecked; rampant

   runaway prices

4. (informal) deserting or revolting against one's group, duties, expected conduct, or the like, especially to establish or join a rival group, change one's life drastically, etc.

   The runaway delegates nominated their own candidate.

• Dictionary.com

This word is frequently used attributively, as in "runaway X" to mean "an X which has run away" or "an X which is out of control".

• run away