n. [ D. ballast; akin to Dan. baglast, ballast, OSw. barlast, Sw. ballast. The first part is perh. the same word as E. bare, adj.; the second is last a burden, and hence the meaning a bare, or mere, load. See Bare, a., and Last load. ] 1. (Naut.) Any heavy substance, as stone, iron, etc., put into the hold to sink a vessel in the water to such a depth as to prevent capsizing. [ 1913 Webster ]

2. Any heavy matter put into the car of a balloon to give it steadiness. [ 1913 Webster ]

3. Gravel, broken stone, etc., laid in the bed of a railroad to make it firm and solid. [ 1913 Webster ]

4. The larger solids, as broken stone or gravel, used in making concrete. [ 1913 Webster ]

5. Fig.: That which gives, or helps to maintain, uprightness, steadiness, and security. [ 1913 Webster ]

It [ piety ] is the right ballast of prosperity. Barrow. [ 1913 Webster ]

Ballast engine, a steam engine used in excavating and for digging and raising stones and gravel for ballast. --
Ship in ballast, a ship carrying only ballast. [ 1913 Webster ]

v. t. [ imp. & p. p. Ballasted; p. pr. & vb. n. Ballasting. ] 1. To steady, as a vessel, by putting heavy substances in the hold. [ 1913 Webster ]

2. To fill in, as the bed of a railroad, with gravel, stone, etc., in order to make it firm and solid. [ 1913 Webster ]

3. To keep steady; to steady, morally. [ 1913 Webster ]

'T is charity must ballast the heart. Hammond. [ 1913 Webster ]

n. (Law) A toll paid for the privilege of taking up ballast in a port or harbor. [ 1913 Webster ]

n. That which is used for steadying anything; ballast. [ 1913 Webster ]

v. t. [ 1st pref. un- + ballast. ] To free from ballast; to discharge ballast from. Totten. [ 1913 Webster ]

a. Not ballasted. [ Obs. & R. ] Addison. [ 1913 Webster ]

a. 1. [ Properly p. p. of unballast. ] Freed from ballast; having discharged ballast. [ 1913 Webster ]

2. [ Pref. un- not + ballasted. ] Not furnished with ballast; not kept steady by ballast; unsteady; as, unballasted vessels; unballasted wits. [ 1913 Webster ]

Unballasted by any sufficient weight of plan. De Quincey. [ 1913 Webster ]

(Naut.) Water confined in specially constructed compartments in a vessel's hold, to serve as ballast. [ 1913 Webster ]