A mechanical model, typically clockwork, illustrating the effect of the earth's diurnal rotation, annual revolution, and obliquity of axis in causing the alternations of day and night and the succession of the seasons. Compare "orrery". Now chiefly historical.
Mid 18th century; earliest use found in Benjamin Martin (bap. 1705, d. 1782), lecturer on science and maker of scientific instruments. Originally from classical Latin tellūr-, tellūs earth + -ian.