solar system UK /ˈsəʊl.ə ˌsɪs.təm/US /ˈsoʊ.lɚ ˌsɪs.təm/ noun2 •Any orbital system of at least one fusor and other heavenly bodies, like planets and other objects.The history of our study of our solar system shows us clearly that accepted and conventional ideas are often wrong, and that fundamental insights can arise from the most unexpected sources. — 1980 •Ellipsis of solar power system (“electric power system that supplies usable solar power by means of photovoltaics”).Almost half of all U.S. households are unable to host a rooftop solar system because they rent or have inadequate roof space. — 2022 formssolar systems