siderostat

noun

sid·​er·​o·​stat

ˈsidərəˌstat

plural -s

: an equatorially mounted mirror moved by clockwork to reflect the rays of a celestial body observed in a constant usually horizontal direction compare heliostat

Word History

Etymology

International Scientific Vocabulary sidero- entry 2 + -stat

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now