Source : Webster's Revised Unabridged Dictionary (1913)

Ballast \Bal"last\, v. t. [imp. & p. p. {Ballasted}; p. pr. &
   vb. n. {Ballasting}.]
   1. To steady, as a vessel, by putting heavy substances in the
      hold.

   2. To fill in, as the bed of a railroad, with gravel, stone,
      etc., in order to make it firm and solid.

   3. To keep steady; to steady, morally.

            'T is charity must ballast the heart. --Hammond.