Siderostat
Pronunciation : Sid"er*o*stat
Part of Speech : n.
Etymology : [L. sidus, sideris, a star + Gr. (Astron.)
Definition : Defn: 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.
Source : Webster's Unabridged Dictionary, 1913