n. & v.
n. 1 any heavy material placed in a ship or the car of a balloon etc. to secure stability. 2 coarse stone etc. used to form the bed of a railway track or road. 3 Electr. any device used to stabilize the current in a circuit. 4 anything that affords stability or permanence.
v.tr. 1 provide with ballast. 2 afford stability or weight to.
[ 16th c.: f. LG or Scand., of uncert. orig. ]