(astronautics) A rocket engine (rocket motor) that uses a solid propellant that, when combusted, generates gases which are used for rocket propulsion. / (astronautics) A rocket that uses such an engine.

plural of solid torus

plural of Platonic solid

Physically very solid; very difficult to move. / (figuratively) Very strong and dependable.

(geometry) The dual polyhedron of any Archimedean solid.

plural of Archimedean solid

plural of Catalan solid

plural of Kepler solid

(simile) Extremely thick and heavy, so as to make it impossible to move. / (simile, of a person) Very reliable and dependable

(topology) The topological space that is a Cartesian product of the two-dimensional disk and the circle.