ballast /ˈbæl.əst/noun 7verb 3forms 3phrases 1 noun7 •Heavy material that is placed in the hold of a ship (or in the gondola of a balloon), to provide stability. •(figurative) Anything that steadies emotion or the mind. •(figurative) That which gives, or helps to maintain, uprightness, steadiness, and security.It [piety] is the right ballast of prosperity. — 1677 •Coarse gravel or similar material laid to form a bed for roads or railroads, or in making concrete; track ballast. •A material, such as aggregate or precast concrete pavers, which employs its mass and the force of gravity to hold single-ply roof membranes in place. •Loose stone or big gravel used to hold rails and tracks in place. •device used for stabilizing current in an electric circuit (e.g. in a tube lamp supply circuit) verb3 •To stabilize or load a ship with ballast. •To weigh down with a ballast.The noosance was […] that to make the umbrella effective he would have to carry abroad such weight to ballast it as would put the whole contraption out of action for carrying abroad at all. — 1938 •To lay ballast on the bed of a railroad track.The task of a Railway Construction Company, R.E., is to lay and ballast the track; [...]. — 1943 formsballasted · ballasting · ballasts Phrases with ballast ballast upTo ballast (stabilize or load with a weight) (something, e.g. a ship).