A room used to grow plants. / A room used to house large machinery (plant), such as air-conditioning equipment.

A display museum in which images of stars and other astronomical phenomena are projected onto a domed ceiling. / An orrery.

(mathematics) the locus of points in the Euclidean plane that satisfies some geometric or algebraic definition; a curve in a plane (as opposed to higher-dimensional space)

(mathematics) Two-dimensional Euclidean space.

An assembly of meshed gears consisting of a central (sun) gear, a coaxial internal gear-wheel and one or more intermediate pinions supported on a revolving carrier.

Any of various flatworms of the order Tricladida living in marine, freshwater, or terrestrial environments.

(beekeeping) Any plant from which bees usually collect nectar, pollen, or both for making honey.

(astronomy) The study of planets, planetary systems and the solar system.

(mathematics) a representation of the space of complex numbers

A series of planks; a group of planks. / The practice of lying face down with arms to the sides, in unusual public spaces, and taking photographs to record the act.