Sid"er*o*stat (?), n. [L. sidus, sideris, a star + Gr. &?;&?;&?; standing, fixed, fr. &?;&?;&?;&?; to place.] (Astron.) An apparatus consisting essentially of a mirror moved by clockwork so as to throw the rays of the sun or a star in a fixed direction; -- a more general term for heliostat.

Sid"er*o*stat (?), n. [L. sidus, sideris, a star + Gr. &?;&?;&?; standing, fixed, fr. &?;&?;&?;&?; to place.] (Astron.) An apparatus consisting essentially of a mirror moved by clockwork so as to throw the rays of the sun or a star in a fixed direction; -- a more general term for heliostat.