runaway

Etymology

run + away

noun

1. A person or animal that runs away or has run away; a person, animal, or organization that escapes captivity or restrictions.
   Runaways are vulnerable to criminal exploitation.
   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. 1556, Ralph Robinson, Utopia: originally printed in Latin, 1516, translation of original by Sir Thomas More, page 96
2. A vehicle (especially, a train) that is out of control.
   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. 1850, “The Romance of the Electric Telegraph”, in New monthly magazine, volume 41
   Runaways are rendered impossible, as the machine can be instantly stopped by means of a double brake connected with the driver's seat 1886, John H. Cooper, “Handling Grain in California”, in Transactions, American Society of Mechanical Engineers, volume 7
   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. 1897, Editor American Machinist, “Runaway Engines and Governors”, in American machinist
   Just south of Wamphray Station, they overtook the runaway. The dim figure of Mitchell could be seen sitting huddled behind the stormboard. They shouted and whistled. He paid no attention. 1950 January, David L. Smith, “A Runaway at Beattock”, in Railway Magazine, page 54
   The former Midland main lines out of Bristol were blocked for more than 18hr after a freight train runaway soon after midnight on February 7. "Jubilee" No. 45615 on the 4.20 p.m. Burton-Bristol freight, which conveyed a quantity of beer, lost control of its train on the 1 in 67 Fishponds incline and ran into the rear of empty stock …. 1962 April, “Motive power miscellany: Western Region”, in Modern Railways, page 280
3. (usually attributive) An object or process that is out of control or out of equilibrium.
   On the chart, the start of a runaway is marked by a box 1989, Gerald Appel, Winning market systems
   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. June 15, 1993, CIO, volume 6, number 14, page 26
   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 2000, F. Matteucci, Franco Giovannelli, The evolution of the Milky Way, page 142
   Where practicable, this passive measure reduces the consequences of a runaway. 2008, Francis Stoessel, Thermal safety of chemical processes, page 257
4. The act of running away, especially of a horse or teams.
   The drivers were generally boys […] They would stop the team when other boats passed and at locks while waiting for the water to rise or fall. They could also be useful in preventing or stopping runaways. Horses were easily startled and might bolt off the tow path or into the canal itself. 2012, John H. White, Jr., Wet Britches and Muddy Boots, page 171
5. An overwhelming victory.
   The home side won in a runaway.

adj

1. Having run away; escaped; fugitive.
   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. Accelerating out of control.
   a runaway train
   a runaway greenhouse effect
4. Unchecked; rampant.
   runaway prices
5. (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.