[bal-uh st]
  1. Nautical. any heavy material carried temporarily or permanently in a vessel to provide desired draft and stability.
  2. Aeronautics. something heavy, as bags of sand, placed in the car of a balloon for control of altitude and, less often, of attitude, or placed in an aircraft to control the position of the center of gravity.
  3. anything that gives mental, moral, or political stability or steadiness: the ballast of a steady income.
  4. gravel, broken stone, slag, etc., placed between and under the ties of a railroad to give stability, provide drainage, and distribute loads.
  5. Electricity.
    1. Also called ballast resistor.a device, often a resistor, that maintains the current in a circuit at a constant value by varying its resistance in order to counteract changes in voltage.
    2. a device that maintains the current through a fluorescent or mercury lamp at the desired constant value, sometimes also providing the necessary starting voltage and current.
verb (used with object)
  1. to furnish with ballast: to ballast a ship.
  2. to give steadiness to; keep steady: parental responsibilities that ballast a person.
  1. in ballast, Nautical. carrying only ballast; carrying no cargo.

Origin of ballast

1450–1500; < Middle Low German, perhaps ultimately < Scandinavian; compare Old Danish, Old Swedish barlast, equivalent to bar bare1 + last load; see last4
Related formsbal·last·er, nounbal·last·ic [buh-las-tik] /bəˈlæs tɪk/, adjectiveo·ver·bal·last, verb (used with object)sub·bal·last, nounun·der·bal·last, verb (used with object) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for ballaster

Historical Examples of ballaster

British Dictionary definitions for ballaster


  1. any dense heavy material, such as lead or iron pigs, used to stabilize a vessel, esp one that is not carrying cargo
  2. crushed rock, broken stone, etc, used for the foundation of a road or railway track
  3. coarse aggregate of sandy gravel, used in making concrete
  4. anything that provides stability or weight
  5. electronics a device for maintaining the current in a circuit
verb (tr)
  1. to give stability or weight to

Word Origin for ballast

C16: probably from Low German; related to Old Danish, Old Swedish barlast, literally: bare load (without commercial value), from bar bare, mere + last load, burden
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ballaster



"heavy material used to steady a ship," 1520s, from Middle English bar "bare" (see bare; in this case "mere") + last "a load, burden," or borrowed from identical terms in North Sea Germanic and Scandinavian (cf. Old Danish barlast, 14c.). "Mere" because not carried for commercial purposes. Dutch balg-last "ballast," literally "belly-load," is a folk-etymology corruption.

Online Etymology Dictionary, © 2010 Douglas Harper