ceiling light fixture; ceiling-mounted luminaire
Technical term used in lighting and interior design; refers to a complete lighting unit designed to be attached directly to the ceiling.
We plan to install a ceiling light fixture in the living room.
シーリングライト is a more common, consumer-friendly term for a ceiling light, while シーリング照明器具 is a formal, technical term often used in specifications or by professionals.
Compound of シーリング (ceiling, from English) + 照明 (lighting) + 器具 (appliance, fixture).