1

ballast

noun bal·last \ ˈba-ləst \

Definition of ballast

1 :a heavy substance (such as rocks or water) placed in such a way as to improve stability and control (as of the draft of a ship or the buoyancy of a balloon or submarine)
  • tossed several tons of ballast overboard
2 :something that gives stability (as in character or conduct)
  • She provided the ballast we needed during stressful times.
3 :gravel or broken stone laid in a railroad bed or used in making concrete
4 :a device used to provide the starting voltage or to stabilize the current in a circuit (as of a fluorescent lamp)
in ballast
of a ship :having only ballast for a load

Recent Examples of ballast from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ballast.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of ballast

probably from Low German, of Scandinavian origin; akin to Danish & Swedish barlast ballast; perhaps akin to Old English bær bare & to Old English hlæst load, hladan to load — more at lade

Other Civil Engineering Terms


2

ballast

verb

Definition of ballast

transitive verb
1 :to steady or equip with or as if with ballast
  • They ballast the canoe with large rocks.
2 :to fill in (something, such as a railroad bed) with ballast (see 1ballast 3)

Origin and Etymology of ballast


BALLAST Defined for Kids

ballast

noun bal·last \ ˈba-ləst \

Definition of ballast for Students

1 :heavy material used to make a ship steady or to control the rising of a balloon
2 :gravel or broken stone laid in a foundation for a railroad or used in making concrete


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