heavy material, such as gravel, sand, or iron, placed in the bilge of a ship to ensure its stability

the hull had insufficient ballast

gravel or coarse stone used to form the bed of a railway track or the substratum of a road

a thick layer of railway ballast

a passive component used in an electric circuit to moderate changes in current

ballasts are permanently wired into existing fixtures

ballast resistors

give stability to (a ship) by putting a heavy substance in its bilge

the vessel has been ballasted to give the necessary floating stability

people insufficiently ballasted with factual information

form (the bed of a railway line or the substratum of a road) with gravel or coarse stone

the track was laid with rails and ballasted with earth